How to rebase master onto a long-lived branch that has been pushed to origin already

rebase-master.sh

## 0.
$ BRANCH_NAME=eqb/my-branch
## 1. Pull down latest remote version of master & branch
$ git checkout master && git pull
$ git checkout $BRANCH_NAME && git pull
## 2. Delete remote branch
$ git push origin --delete $BRANCH_NAME
## 3. Remove dangling reference to origin
$ git branch --unset-upstream
## 4. Apply changes from master on branch
$ git rebase master
## 5. (optional) Push branch back to origin
$ git push origin