git clone <git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git>
cd into/cloned/fork-repo
git remote add upstream <git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git>
git fetch upstream
git pull upstream <branch name>
git push
git clone <git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git>
cd into/cloned/fork-repo
git remote add upstream <git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git>
git fetch upstream
git pull upstream <branch name>
git push