If a Dibs Item has been claimed by the wrong athlete profile or fulfiller name, the only way to update that information is to mark the Dibs Item as Unclaimed and then have the user claim that item again.
Sign in and turn on Edit Mode.
Click on the Dibs tab.
Click on the Dibs Session "name."
Click on the Dibs Item "name."
On the bottom-right side of the page, under the Admin Actions header, click Mark Unclaimed.
Click Mark Unclaimed again.
The user must that Dibs Item again under the correct athlete/fulfiller name.