I watched the video on how to fix the shower door...I've tried it 7 times and it has not worked yet. The right side is lower than the left, and once I put the drip rail on, it doesn't close. There is not enough room for the rubber part to go through the door. The right side hangs lower than the left. I am able to loosen 3 of the four corners of screws as in the video. The bottom left screw is totally stripped. I cannot remove it. It's been in there a long time and won't come out. Can anyone please tell me what I can do to fix this?