git checkout -b <branchname>
git add
git commit -m "description of changes"
git checkout master
git pull --rebase
git checkout <branchname>
git rebase master
In case of conflicts: resolve conflict by looking at the files in question.
git add <resolved files>
git rebase --continue
git rebase --interactive HEAD~N
alternativelly create pull request and merge changes to master via UI
git checkout master
git merge <branchname>
git push
git branch -d <branchname>
git push origin :<branchname>