git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
git fetch upstream
git checkout master
git rebase upstream/master
git checkout BRANCH
git merge master
git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git
git fetch upstream
git checkout master
git rebase upstream/master
git checkout BRANCH
git merge master