A buyer can edit only neutral and negative feedbacks, if the seller sends the buyer a Feedback Revision Request, and the buyer acts, before the feedback has been posted for thirty days. The seller will find a link on her/his feedback profile to make that request. If for some reason the seller can't find the link there, there's another link (a button) on this Help page: https://www.ebay.com/help/selling/leaving-feedback-buyers/replying-feedback-received-item-sold?id=41...
