Remove a Branch from Server

git branch -D branchname
git push origin :branchname # or delete at github.com after PR is merged
git remote prune origin

Copy File from Branch A to Branch B

git checkout branchB
git checkout branchA filename
git commit -m "Adding filename to branchB"

Force Local master to Be Same as upstream/master 

git checkout master
git reset --hard upstream/master  
git push origin master --force