Discard previous commit and force push to remote

re

https://stackoverflow.com/a/24659189

Move you branch pointer back to the first commit:
git reset --hard HEAD~

Stage the changes from the previous commit:

git merge --squash HEAD@{1}
Commit your changes, amending them into a single commit.

git commit --amend
Force-push your new single commit to the server:

git push -f