If you are on the branch you want to rename:
git branch -m new-name
If you are on a different branch:
git branch -m old-name new-name
git push origin :old-name new-name
Switch to the branch and then:
git push origin -u new-name
If you are on the branch you want to rename:
git branch -m new-name
If you are on a different branch:
git branch -m old-name new-name
git push origin :old-name new-name
Switch to the branch and then:
git push origin -u new-name