git reset --hard HEAD~1The HEAD~1 means the commit before head. Or, you could look at the output of git log, find the commit id of the commit you want to back up to, and then do this:
git reset --hardIf you already pushed it, you will need to do a force push to get rid of it...
git push origin HEAD --forceHowever, if others may have pulled it, then you would be better off starting a new branch. Because when they pull, it will just merge it into their work, and you will get it pushed back up again. If you already pushed, it may be better to use git revert, to create a "mirror image" commit that will undo the changes. However, both commits will both be in the log.
git reset --hard HEAD... is great if you want to get rid of WORK IN PROGRESS. It will reset you back to the most recent commit, and erase all the changes in your working tree and index. Lastly, if you need to find a commit that you "deleted", it is typically present in git reflog unless you have garbage collected your repository.
HEAD~1 or just HEAD^. If you pushed, you should use git revert instead.