1. Fork their repo on Github
2. In your local, rename your origin remote to upstream
git remote rename origin upstream
3. Add a new origin
git remote add origin git@github...my-fork
4. Fetch & push
git fetch origin
git push origin1. Fork their repo on Github
2. In your local, rename your origin remote to upstream
git remote rename origin upstream
3. Add a new origin
git remote add origin git@github...my-fork
4. Fetch & push
git fetch origin
git push origin