The Submitter (not co-presenter) can edit submission.
To edit submission, log into the ABC site and click My Profile, then click My Options. Next, select My Presentations (at bottom of list—lower right corner). Click your 2021 conference submission.
From the submission, find pencil icon on left. After clicking the pencil, edit as desired. Please answer the questions regarding number of in-person and virtual presenters and time zone preferences if presenting virtually. Go to bottom and press OK when done.