Enter Windows Git shell and launch
git clone https://github.com/visionmedia/git-extras cd git-extras cp bin/* /libexec/git-core/
Last command differs from original installation instructions. Launching
make install which will not work even if you install make for Windows.
I just copy bins where are located Windows Git shell ones. It seems tough but it works, and enables autocompletion too.
Not all commands will work, for example
git extras will fail cause
man is not installed.
The It works flag will be added as soon as I will try commands.
Click on the command to read its documentation on git-extras Readme.md.