Once you have your copy of Git-Blog setting it up is a matter of just making the path where Git-Blog is located accessible by your webserver. This can be any location in your webserver path, Git-Blog should automatically adjust the URL paths based on the path it is being served from.
Your webserver must support .htaccess files and allow overriding of Rewrite rules. This means that you should enable the FileInfo override for the directory where Git-Blog will be located, or any parent directory:
<directory /Path/To/Git-Blog/> AllowOverride FileInfo </directory>
The last step is to branch the code so you can make your edits away from the main branch of the code.
git branch MyWebSite
You can then make any changes you wish to the site without affecting the upstream branch. Future updates to the workings of Git-Blog can be included by pulling in the changes from the main branch into your website branch. Your first few steps would likely be to remove this Git-Blog documentation and other related files from your branch.