have a wireless keyboard and trackpad that are both suffering the same symptom: I can't remove the screw cover to replace the AA batteries.

any recommendations???

Apply a warm heating pad to the area, try again. Then apply a cold pack to the area. Rapid temperature shifts may break loose the aluminum oxide from the batteries failing.

Probably some battery corrosion. I've successfully unstuck one of two with carefully applied vinegar that works thru the corrosion. The other... I'm not sure. About at the point of applying heat though figure that become destructive at some point.

Agree about battery corrosion. A tiny drop of a synthetic motor oil to the edge of the cap. Give it ten minutes to penetrate and give it a try. Synthetic can penetrate the threads better then other oils. My 2 cents.