What have you tried?
Did you go to Revise My Item and delete the picture from the Sell Your Item form? It's the little trash can under the picture.
You should have your replacement handy if this is your only photo, because a picture of something is mandatory.
If you have no bids, you could just close the listing and start again. Cut and paste your description onto a word or text document with all the HTML coding ready to re-insert. That's usually the longest part of making a listing for me.
