The backing plate is a square with all three hinges bolts, threaded into it, so it is not possible to spin the threaded backing plate. It is held, loosely, in place by a light-gauge wrap, spot-welded to the backside of the "A" pillar and the only way to remedy a problem is to cut the area out, make the repair and weld it back together, unless you can use an easy-out to remove the damaged bolt and retap it.
