Removing stripped screws from MacBook Pro back case
Whichever method you follow, be very, very careful. The worst case scenario may require drilling the screw out.

Try placing a wide rubber band on the screw and use a slightly bigger screwdriver. Instead of a rubber band, you could also try with a piece of cloth (anything that can provide more grip and change its shape a bit).

For other methods, see The 12 Best Ways to Remove Stripped Screws.

You could also try iFixit's Precision Screw Extractor Set.