The iPhone 4 is brand new, but accidents still happen - even right after you get it, right? So, if you have cracked or scratched up your screen and can no longer use it, check out this tutorial. Apple won't fix the damage if they think you did it, and a repair shop will charge tons of money. This tutorial will walk you through how to take the screen off on your own and replace it with a brand new one. Be careful and maybe think about investing in a case next time.