If you happen to come into the situation that your master branch is screwed (e.g. by falsely merging and reverting other/old branches into the master) you might need to replace your master with another branch (like your develop branch). That is actually pretty easy, all you need to do is executing the following git commands:
git checkout develop git merge -s ours master git checkout master git merge develop
After you executed the commands your master branch is completely up-to-date with your develop branch.