From inside the forked repository, add a new remote pointing to the upstream repo:
$ git remote add upstream git://github.com/upstream/repo.gitThen change the master branch to track upstream/master.
$ git checkout -b anything
$ git branch -D master
$ git checkout --track upstream/master
$ git branch -D anything$ git pull
$ git checkout -b new-changes
$ # make bump changes
$ git commit
$ git push --set-upstream origin new-changes
$ # make PR from browser
$ # wait for PR to be merged
$ git checkout master
$ git branch -D new-changes