I've had to do this to a few phones, and I can tell you from experience that it is very useful to have a guide on how to disassemble a phone. My Vogue's screen cracked and I had to replace it, there was already a guide, so that was pretty easy. My Eris got a ton of dust under the screen and there was no guide anywhere, it took me a month or so to figure out how to do it. Most recently, my Incredible got some dust under the screen as well, but luckily I bought it direct from VZW, so I could just return it. Those were all HTC devices, so I'm really hoping that the X has a little better build quality(much like the Droid), so I don't ever have to attempt this.