Well, now that you've stripped the screws you might be in a real "sorry, tough luck" scenario. You should have noticed the screw heads stripping because the screwdriver was popping out of the screw, jumping rather than turning.
What you could do, IF you have enough left on the head of the screw, is to use an impact driver. You probably don't want to spend the $200 to buy one, but borrow one from any friend of yours who does construction. It looks like an electric drill, but what it does is completely different. It's a miniature version of the impact gun they use on cars to free rusted and torqued big bolts.
All you need to do is use the right size screwdriver bit on it, and it'll hammer them free. You'll be mind-blown at how easy it is.
But if the screw heads are too stripped, you might be out of luck.