I found the spare tire cover to be impossible to install and have access to the attaching nut.
Xtreme Upholstery, 709 Dallas Dr. Denton, TX Phn 940-380-8778 sewed in a commercial 9 inch zipper. Now I can install the cover over the tire on the hangar floor. Place it on the bumper and reach in through the unzipped opening to install washers and nut. The cover is sandwiched at the bottom by the bumper and top by contact with the camper shell.