If it’s stripped screws then maybe try different screw bits? One might get some traction. or maybe try unscrewing it with an elastic band in between that might help.
If that doesn’t work you could try some screw-extracting pliers.
If that really doesn’t work you could also try putting a small dot of superglue on the screw, let the screwdriver head dry in it then try turning it.
If that really, really doesn’t work you could try using a rotary tool/dremel/knife to cut a small line that you could use a flathead to unscrew it with.
Or do you mean like the actual head has come off? :o