diff --git a/.gitignore b/.gitignore
index c7191ed..910d521 100644
--- a/.gitignore
+++ b/.gitignore
@@ -233,4 +233,5 @@ Makefile
 UEFIExtract/UEFIExtract
 UEFIFind/UEFIFind
 UEFIPatch/UEFIPatch
-UEFITool
\ No newline at end of file
+UEFIReplace/UEFIReplace
+UEFITool
diff --git a/UEFIReplace/uefireplace.cpp b/UEFIReplace/uefireplace.cpp
new file mode 100644
index 0000000..f4ff1ea
--- /dev/null
+++ b/UEFIReplace/uefireplace.cpp
@@ -0,0 +1,108 @@
+/* uefireplace.cpp
+
+Copyright (c) 2017, mxxxc. All rights reserved.
+This program and the accompanying materials
+are licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution.  The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+*/
+
+#include "uefireplace.h"
+
+UEFIReplace::UEFIReplace(QObject *parent) :
+    QObject(parent)
+{
+    ffsEngine = new FfsEngine(this);
+    model = ffsEngine->treeModel();
+}
+
+UEFIReplace::~UEFIReplace()
+{
+    delete ffsEngine;
+}
+
+UINT8 UEFIReplace::replace(QString inPath, const QByteArray & guid, const UINT8 sectionType, const QString contentPath)
+{
+    QFileInfo fileInfo = QFileInfo(inPath);
+    if (!fileInfo.exists())
+        return ERR_FILE_OPEN;
+
+    fileInfo = QFileInfo(contentPath);
+    if (!fileInfo.exists())
+        return ERR_FILE_OPEN;
+
+    QFile inputFile;
+    inputFile.setFileName(inPath);
+
+    if (!inputFile.open(QFile::ReadOnly))
+        return ERR_FILE_READ;
+
+    QByteArray buffer = inputFile.readAll();
+    inputFile.close();
+
+    UINT8 result = ffsEngine->parseImageFile(buffer);
+    if (result)
+        return result;
+
+    QFile contentFile;
+    contentFile.setFileName(contentPath);
+
+    if (!contentFile.open(QFile::ReadOnly))
+        return ERR_FILE_READ;
+
+    QByteArray contents = contentFile.readAll();
+    contentFile.close();
+
+    result = replaceInFile(model->index(0, 0), guid, sectionType, contents);
+    if (result)
+        return result;
+
+    QByteArray reconstructed;
+    result = ffsEngine->reconstructImageFile(reconstructed);
+    if (result)
+        return result;
+    if (reconstructed == buffer)
+        return ERR_NOTHING_TO_PATCH;
+
+    QFile outputFile;
+    outputFile.setFileName(inPath.append(".patched"));
+    if (!outputFile.open(QFile::WriteOnly))
+        return ERR_FILE_WRITE;
+
+    outputFile.resize(0);
+    outputFile.write(reconstructed);
+    outputFile.close();
+
+    return ERR_SUCCESS;
+}
+
+UINT8 UEFIReplace::replaceInFile(const QModelIndex & index, const QByteArray & guid, const UINT8 sectionType, const QByteArray & newData)
+{
+    if (!model || !index.isValid())
+        return ERR_INVALID_PARAMETER;
+    if (model->subtype(index) == sectionType) {
+        QModelIndex fileIndex = model->findParentOfType(index, Types::File);
+        QByteArray fileGuid = model->header(fileIndex).left(sizeof(EFI_GUID));
+        if (fileGuid == guid) {
+            return ffsEngine->replace(index, newData, REPLACE_MODE_BODY);
+        }
+    }
+
+    bool patched = false;
+    if (model->rowCount(index) > 0) {
+        for (int i = 0; i < model->rowCount(index); i++) {
+            UINT8 result = replaceInFile(index.child(i, 0), guid, sectionType, newData);
+            if (!result) {
+                patched = true;
+                break;
+            } else if (result != ERR_NOTHING_TO_PATCH)
+                return result;
+        }
+    }
+
+    return patched ? ERR_SUCCESS : ERR_NOTHING_TO_PATCH;
+}
diff --git a/UEFIReplace/uefireplace.h b/UEFIReplace/uefireplace.h
new file mode 100644
index 0000000..682a1f6
--- /dev/null
+++ b/UEFIReplace/uefireplace.h
@@ -0,0 +1,41 @@
+/* uefireplace.h
+Copyright (c) 2017, mxxxc. All rights reserved.
+This program and the accompanying materials
+are licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution.  The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+*/
+
+#ifndef __UEFIREPLACE_H__
+#define __UEFIREPLACE_H__
+
+#include <QObject>
+#include <QByteArray>
+#include <QString>
+#include <QStringList>
+#include <QFileInfo>
+#include <QUuid>
+
+#include "../basetypes.h"
+#include "../ffs.h"
+#include "../ffsengine.h"
+
+class UEFIReplace : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit UEFIReplace(QObject *parent = 0);
+    ~UEFIReplace();
+
+    UINT8 replace(const QString inPath, const QByteArray & guid, const UINT8 sectionType, const QString contentPath);
+
+private:
+    UINT8 replaceInFile(const QModelIndex & index, const QByteArray & guid, const UINT8 sectionType, const QByteArray & contents);
+    FfsEngine* ffsEngine;
+    TreeModel* model;
+};
+
+#endif
diff --git a/UEFIReplace/uefireplace.pro b/UEFIReplace/uefireplace.pro
new file mode 100644
index 0000000..e3d853d
--- /dev/null
+++ b/UEFIReplace/uefireplace.pro
@@ -0,0 +1,42 @@
+QT       += core
+QT       -= gui
+
+TARGET    = UEFIReplace
+TEMPLATE  = app
+CONFIG   += console
+CONFIG   -= app_bundle
+DEFINES  += _CONSOLE
+
+SOURCES  += uefireplace_main.cpp \
+ uefireplace.cpp \
+ ../types.cpp \
+ ../descriptor.cpp \
+ ../ffs.cpp \
+ ../ffsengine.cpp \
+ ../peimage.cpp \
+ ../treeitem.cpp \
+ ../treemodel.cpp \
+ ../LZMA/LzmaCompress.c \
+ ../LZMA/LzmaDecompress.c \
+ ../LZMA/SDK/C/LzFind.c \
+ ../LZMA/SDK/C/LzmaDec.c \
+ ../LZMA/SDK/C/LzmaEnc.c \
+ ../Tiano/EfiTianoDecompress.c \
+ ../Tiano/EfiTianoCompress.c \
+ ../Tiano/EfiTianoCompressLegacy.c
+
+HEADERS  += uefireplace.h \
+ ../basetypes.h \
+ ../descriptor.h \
+ ../gbe.h \
+ ../me.h \
+ ../ffs.h \
+ ../peimage.h \
+ ../types.h \
+ ../ffsengine.h \
+ ../treeitem.h \
+ ../treemodel.h \
+ ../LZMA/LzmaCompress.h \
+ ../LZMA/LzmaDecompress.h \
+ ../Tiano/EfiTianoDecompress.h \
+ ../Tiano/EfiTianoCompress.h
diff --git a/UEFIReplace/uefireplace_main.cpp b/UEFIReplace/uefireplace_main.cpp
new file mode 100644
index 0000000..562db22
--- /dev/null
+++ b/UEFIReplace/uefireplace_main.cpp
@@ -0,0 +1,78 @@
+/* uefireplace_main.cpp
+
+Copyright (c) 2017, mxxxc. All rights reserved.
+This program and the accompanying materials
+are licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution.  The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+*/
+#include <QCoreApplication>
+#include <QString>
+#include <QStringList>
+#include <iostream>
+#include "uefireplace.h"
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication a(argc, argv);
+    a.setOrganizationName("CodeRush");
+    a.setOrganizationDomain("coderush.me");
+    a.setApplicationName("UEFIReplace");
+
+    UEFIReplace r;
+    UINT8 result = ERR_SUCCESS;
+    QStringList args = a.arguments();
+
+    if (args.length() < 5) {
+        std::cout << "UEFIReplace 0.3.9 - UEFI image file replacement utility" << std::endl << std::endl <<
+            "Usage: UEFIReplace image_file guid section_type contents_file" << std::endl;
+        return ERR_SUCCESS;
+    }
+
+    QUuid uuid = QUuid(args.at(2));
+    QByteArray guid = QByteArray::fromRawData((const char*)&uuid.data1, sizeof(EFI_GUID));
+    bool converted;
+    UINT8 sectionType = (UINT8)args.at(3).toUShort(&converted, 16);
+    if (!converted)
+        result = ERR_INVALID_PARAMETER;
+    else
+        result = r.replace(args.at(1), guid, sectionType, args.at(4));
+
+    switch (result) {
+    case ERR_SUCCESS:
+        std::cout << "File replaced" << std::endl;
+        break;
+    case ERR_INVALID_PARAMETER:
+        std::cout << "Function called with invalid parameter" << std::endl;
+        break;
+    case ERR_INVALID_FILE:
+        std::cout << "Invalid/corrupted file specified" << std::endl;
+        break;
+    case ERR_INVALID_SECTION:
+        std::cout << "Invalid/corrupted section specified" << std::endl;
+        break;
+    case ERR_NOTHING_TO_PATCH:
+        std::cout << "No replacements can be applied to input file" << std::endl;
+        break;
+    case ERR_NOT_IMPLEMENTED:
+        std::cout << "Can't replace body of this section type" << std::endl;
+        break;
+    case ERR_FILE_OPEN:
+        std::cout << "Input file not found" << std::endl;
+        break;
+    case ERR_FILE_READ:
+        std::cout << "Input file can't be read" << std::endl;
+        break;
+    case ERR_FILE_WRITE:
+        std::cout << "Output file can't be written" << std::endl;
+        break;
+    default:
+        std::cout << "Error " << result << std::endl;
+    }
+
+    return result;
+}