I once had a screw on a laptop that wouldn’t unscrew and eventually somewhat lost its shape. I had asked my uncle for help, who gave me the solution. I think it was slightly less bad than this, but it might help:

1. Apply WD40 around the edges of the screw, such that it could enter the hole
2. Apply it to the screw head
3. Hold your screwdriver in the hole and gently tap it with a hammer a couple of times
4. Slowly attempt to screw it out, whilst applying firm downward pressure on the screw

Note that the amounts of WD40 you have to apply are tiny. We’re talking drops of the stuff. It might be best to attempt to spray something else, and use the residue on the nozzle to apply it