The refpolicy repository is still svn. heres how to use git together with svn.
1. use git svn to clone the refpolicy svn repository:
git svn clone http://oss.tresys.com/repos/refpolicy/trunk refpolicy
git branch (to see if master is there)
git branch -r (to see if remote branch (git-svn) is there)
2. create a branch to work on.
git svn checkout -b mybranch git-svn
3. add changes and commit them
4. create a patch with your modification (your changes from master in this case)
git format-patch master
5. update master and git-svn (remote branche)
git svn fetch
note eclipse-egit is a eclipse plugin that allows you to load, work on a git branch in eclipse and commit.