Git - Rename a branch locally and in remote

Git-RenameBranchName

1. Rename your local branch.
      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

2. Delete the old-name remote branch and push the new-name local branch.
      git push origin :old-name new-name

3. Reset the upstream branch for the new-name local branch.
      Switch to the branch and then:
        git push origin -u new-name
        
Ref : https://multiplestates.wordpress.com/2015/02/05/rename-a-local-and-remote-branch-in-git/