diff --git a/README.md b/README.md
index cdec1de99..99e1bcec4 100644
--- a/README.md
+++ b/README.md
@@ -1,42 +1,100 @@
-### Building Dive host tool in Windows
+### Checkout the code
+
+```
+git clone --recursive https://github.com/google/dive.git
+```
+
+If the code has been checked out without `--recursive` or you're pulling from the main branch later, please run following command to make sure the submodules are retrieved properly.
+```
+git submodule update --init --recursive
+```
+
+### Prerequisite
+
+ - The QT framework, can be installed from [QT online installer](https://download.qt.io/archive/online_installers/4.6/). We are currently using QT 5.11.2
+ - gRPC [dependencies](https://github.com/grpc/grpc/blob/master/BUILDING.md#pre-requisites)
+ - Android NDK (currently we are using 25.2.9519653). Set the `ANDROID_NDK_HOME` environment variable.
+  ```
+    export ANDROID_NDK_HOME=~/andriod_sdk/ndk/25.2.9519653
+  ``` 
+
+### Building Dive host tool on Linux
+```
+# Assumes QTDIR is set to gcc_64 directory (eg. ~/Qt/5.11.2/gcc_64)
+export CMAKE_PREFIX_PATH=$QTDIR
+export PATH=$QTDIR:$PATH
+cd <dive_path>
+git submodule update --init --recursive
+mkdir build
+cd build
+cmake -GNinja ..
+ninja
+```
+
+You can specify the build type for debug/release as well
+with `-DCMAKE_BUILD_TYPE=Debug` or `-DCMAKE_BUILD_TYPE=Release` when running cmake.
+
+### Building Dive host tool on Windows
+To build with prebuilt gRPC libraries: 
 ```
 REM Assumes QTDIR is set to msvc directory (eg. C:\Qt\5.11.2\msvc2017_64)
 set CMAKE_PREFIX_PATH=%QTDIR%
 set PATH=%QTDIR%\bin;%PATH%
 cd <dive_path>
-git submodule update --init
+git submodule update --init --recursive
 mkdir build
 cd build
 cmake -G "Visual Studio 17 2022" ..
 ```
-Open `dive.sln` and build in Debug or Release
+
+Open `dive.sln` and build in Debug or Release 
 Or run:
+```
 cmake --build . --config Debug
 cmake --build . --config Release
+```
+#### Build without prebuilt libraries
+
+Or you can build without using the prebuilt libraries with `-DBUILD_GRPC=ON`
 
-### Building Dive host tool in Linux (DEBUG)
 ```
-REM Assumes QTDIR is set to gcc_64 directory (eg. ~/Qt/5.11.2/gcc_64)
-export CMAKE_PREFIX_PATH=$QTDIR
-export PATH=$QTDIR:$PATH
-cd <dive_path>
-git submodule update --init --recursive
-mkdir build
+cmake -G "Visual Studio 17 2022" -DBUILD_GRPC=ON ..
+```
+
+Or you can build with Ninja, which is much faster:
+Open Developer Command Prompt for VS 2022(or 2019) and run:
+```
 cd build
-cmake -DCMAKE_BUILD_TYPE=Debug ..
-make -j$(nproc)
+cmake -G "Ninja" -DBUILD_GRPC=ON ..
+ninja
 ```
 
+Note this requires build dependencies for gRPC, which requires to install prerequisite listed at [gRPC website](https://github.com/grpc/grpc/blob/master/BUILDING.md#windows). It's mostly about install the [NASM](https://www.nasm.us/). If you don't have `choco` installed, you can download the binary from [NASM website](https://www.nasm.us/) and add its path to the `PATH` environment variable. 
+
+#### Update prebuilt libraries
+Currently, the gRPC binaries are prebuilt under the folder `prebuild``. In case there's build error with the prebuilt libraries, you can run regenerate the libraries with following steps:
+ - Open Developer Command Prompt for VS 2022(or 2019)
+ - Run `scripts/build_grpc.bat`
+
+
 ### Building Android Libraries
 
 - Download the Android NDK (e.g. 25.2.9519653)
 - Set the environment variable `ANDROID_NDK_HOME` (e.g. export ANDROID_NDK_HOME=~/andriod_sdk/ndk/25.2.9519653)
 Run the script 
 
+On Linux, run: 
 ```
 ./scripts/build_android.sh
 ```
+And on Windows, Open Developer Command Prompt for VS 2022(or 2019) and run 
+
+```
+scripts\build_android.bat
+```
+
+
 
-It will build both debug and release version of the libraries.
+It will build both debug and release version of the libraries under `build_android` folder.
 
 
diff --git a/grpc.cmake b/grpc.cmake
index 0aecd7646..c6d0eb8e9 100644
--- a/grpc.cmake
+++ b/grpc.cmake
@@ -68,7 +68,7 @@ if(GRPC_AS_SUBMODULE)
   set(_REFLECTION grpc++_reflection)
   if(CMAKE_CROSSCOMPILING)
     if(CMAKE_HOST_WIN32)
-      set(_PROTOBUF_PROTOC "${CMAKE_SOURCE_DIR}/bin/protoc.exe")
+      set(_PROTOBUF_PROTOC "${CMAKE_SOURCE_DIR}/prebuild/grpc/bin/protoc.exe")
     else()
       find_program(_PROTOBUF_PROTOC protoc PATHS ${CMAKE_SOURCE_DIR}/bin)
     endif()
@@ -81,7 +81,7 @@ if(GRPC_AS_SUBMODULE)
   set(_GRPC_GRPCPP grpc++)
   if(CMAKE_CROSSCOMPILING)
     if(CMAKE_HOST_WIN32)
-      set(_GRPC_CPP_PLUGIN_EXECUTABLE "${CMAKE_SOURCE_DIR}/bin/grpc_cpp_plugin.exe")
+      set(_GRPC_CPP_PLUGIN_EXECUTABLE "${CMAKE_SOURCE_DIR}/prebuild/grpc/bin/grpc_cpp_plugin.exe")
     else()
       find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin PATHS ${CMAKE_SOURCE_DIR}/bin)
     endif()
diff --git a/scripts/build_android.bat b/scripts/build_android.bat
index 21e0a78a0..2a2fb3484 100644
--- a/scripts/build_android.bat
+++ b/scripts/build_android.bat
@@ -12,11 +12,12 @@
 :: See the License for the specific language governing permissions and
 :: limitations under the License.
 
-@REM @echo off
+@echo off
 
 set PROJECT_ROOT=%~dp0\..
 set BUILD_TYPE=Debug Release
 set SRC_DIR=%PROJECT_ROOT%
+set startTime=%time%
 
 (for %%b in (%BUILD_TYPE%) do (
     setlocal enabledelayedexpansion
@@ -24,11 +25,10 @@ set SRC_DIR=%PROJECT_ROOT%
     set build=%%b
     set BUILD_DIR=%PROJECT_ROOT%\\build_android\\!build!
     echo "BUILD_DIR: " !BUILD_DIR!
-    mkdir !BUILD_DIR!
+    md !BUILD_DIR!
     pushd !BUILD_DIR!
     cmake  -DCMAKE_TOOLCHAIN_FILE=%ANDROID_NDK_HOME%/build/cmake/android.toolchain.cmake ^
-        -G "Unix Makefiles"^
-        -DCMAKE_MAKE_PROGRAM="make" ^
+        -G "Ninja"^
         -DCMAKE_BUILD_TYPE=!build!  ^
         -DCMAKE_SYSTEM_NAME=Android ^
         -DANDROID_ABI=arm64-v8a ^
@@ -43,4 +43,7 @@ set SRC_DIR=%PROJECT_ROOT%
 
     cmake --build . --config=!build! -j %NUMBER_OF_PROCESSORS%
     popd
-))
\ No newline at end of file
+))
+
+echo Start Time: %startTime%
+echo Finish Time: %time%
\ No newline at end of file