fork gaia on github
then clone your fork locally
create a branch locally, add your changes, do your commit
then git push --force origin branch
this will push your local git branch to your github clone
then you can visit your githb fork and click "create pull request"
No, the commit message does not have to be exactly the same as bug title, but we would encourage it to contains at least the bug number so that we could cross-ref your commit back to this bug.