Ensure you have cloned this repository and checked out the gh-pages branch (git checkout gh-pages)
Ensure the local copy of the repo is up to date with the remote (git pull)
Edit the file you want to edit (emacs /path/to/file.ext) :)
Stage your changes (git add /path/to/edited/file.ext /path/to/other/edited/file.ext)
Commit your staged changes (git commit -m "Your commit message, do better then this one")
Push your changes to the remote repo (git push)