I needed to unmount a drywall ceiling diffuser to do a small fix. The diffuser is a "traditional" stainless still box mounted using two screws driven straight into the sheetrock. Unfortunately the builder did a pretty sloppy job and the opening was too large so the screws barely held. Unmounting them effectively cause the holes to crumble so now there is no easy way to screw them back in. Here's a photo of the opening (note how the screwholes have zero clearance from the opening sides):
I've tried to rotate the diffuser 90 deg. but it doesn't help as the opening is still large.
Question: can anyone suggest a trick (or a mounting kit, or a different kind of a diffuser) to put it back on the ceiling?