To revert to a commit that’s older than the most recent commit:
Source: https://stackoverflow.com/questions/4114095/how-do-i-revert-a-git-repository-to-a-previous-commit
# Resets index to former commit; replace '56e05fced' with your commit code
git reset 56e05fced
# Moves pointer back to previous HEAD
git reset --soft HEAD@{1}
git commit -m "Revert to 56e05fced"
# Updates working copy to reflect the new commit
git reset --hard