How do I fix striped screws?

I recently bought a 2ds to play on but it came in with a broken screen. I didn’t feel like returning it because the repairs look easy. When I was unscrewing the back screws I added too much pressure so in result two of the screws became striped of its grip. I tried a few methods like using a rubber band, using a bigger screwdriver, and using super glue to a stick a popsicle stick to the screw. None of the methods worked and now am stuck and don’t know what to do.