Git
Reset local repository branch to remote HEAD
git fetch origin
git reset --hard origin/master
Sync a fork with the original upstream repository via rebase
git remote add upstream https://github.com/{original_developer}/{repository}
git fetch upstream
git rebase upstream/master
# may need: git push --force
Remove latest commits from repository
To remove commits from local repository:
# Replace n with a number of the commits you want to check to remove
git rebase -i HEAD~n
To undo pushed commits to remote repository:
# Undo latest commit on remote, to undo more commits add more ^ after HEAD
git push -f origin HEAD^:master