You've submitted a pull request ("PR") against the Elgg repo and core members have asked you to make some changes.

Check out your work branch in case you've been working on something else in your local repo:

cd ~/htdocs/elgg18
git checkout my-branch-name

Make your changes as necessary, test and commit them. Your later commit messages don't necessarily need to include the ticket number.

To update your PR, just re-push to your github repo:

git push fork my-branch-name

On the PR page you'll see the additional commits at the bottom. If you think necessary, add a brief note describing the changes.

That's it!