git checkout -b 2.0-oss <existing oss branch> # keep the commits to rebase
#git rebase -i <fork point> # rebase to tidy patches (as needed)
# equivalent to `git reset --hard <upstream/2.0 branch> && git cherry-pick <fork point>..<existing oss branch>`
git rebase --onto <upstream/2.0 branch> <fork point> 2.0-oss