I. Prerequisite
a. Microsoft Visual Studio: https://www.visualstudio.com
b. CMake for Windows: https://cmake.org/download
c. Git For Windows: https://git-scm.com/download/win
II. Acquire the Source
a. Open cmd and go to c:\ directory
b. git clone https://github.com/opencv/opencv.git
c. git clone https://github.com/opencv/opencv_contrib