git fetch upstream
git checkout master
git merge upstream/master
git push origin master
See: this GitHub Help page and "Keeping up with Upstream" in Git Pro: 6.2 GitHub - Contributing to a Project
git fetch upstream
git checkout master
git merge upstream/master
git push origin master
See: this GitHub Help page and "Keeping up with Upstream" in Git Pro: 6.2 GitHub - Contributing to a Project