$ git push --delete <remote_name> <branch_name>
$ git branch -d <branch_name>
$ git diff <local branch> <remote>/<remote branch>
Note: This assumes you have a local branch that tracks a remote one, and your information is up to date.
$ git checkout -b <branch_name>
Then:
$ git branch --set-upstream-to <remote_name> <branch_name>
or
$ git push -u <remote_name> <branch_name>
or
git push -u origin HEAD
$ git fetch <remote_name> <branch_name>
Set upstream to the original that was forked:
$ git remote add upstream
Fetch data (git fetch fetches from origin by default)
$ git fetch upstream