You have to download your project and place to a folder.

$ tar xzf project.tar.gz
$ cd project
$ git init-db

This will initialize your project on git.now you have to add files which will monitored via git.

$ git add .

these means git will monitor all files.

$ git commit -a

This will prompt a message to commit.
Try modifying some files, then run

$git diff

to review your changes.