1 git commit --amend

2 git push -f

git push --help

       -f, --force
           Usually, the command refuses to update a remote ref that is not an ancestor of the local ref used to overwrite it. Also, when --force-with-lease option
           is used, the command refuses to update a remote ref whose current value does not match what is expected.


           This flag disables these checks, and can cause the remote repository to lose commits; use it with care.


           Note that --force applies to all the refs that are pushed, hence using it with push.default set to matching or with multiple push destinations
           configured with remote.*.push may overwrite refs other than the current branch (including local refs that are strictly behind their remote counterpart).
           To force a push to only one branch, use a + in front of the refspec to push (e.g git push origin +master to force a push to the master branch). See the
           <refspec>...  section above for details.