GitForSiteConf

Before starting to edit a file:

git pull --rebase

Then, edit the file, then:

git commit -a -m "Some other test change."
git push origin master

All information can be found on the cms twiki:
https://twiki.cern.ch/twiki/bin/view/CMSPublic/CompOpsSiteconfMigrationToGit

Remark that you need to be on lxplus to be able to commit.