I'm trying to replace both my front and back screen on my phone and I've tried pretty much everything. The whole rubber band trick, super glue, etc....

All of the screws on the back aren't coming off and I don't know why. I think it's because of my screwdriver. But, I really would not like to purchase another one because I just want my phone fixed asap. I've literally tried everything and the battery screw is totally jacked up now. PLEASE HELP. And provide specific directions because I have no idea how to do this stuff...