Broke my screen due to carelessness... And a bouncy bed that made it fly off the bed and into the metal frame of it! Whoops!
Let me clear something up first though, this is a glass part infront of the LCD screen, if your picture is distorted or if the touch screen is not working you will need to purchace the £120 or so product to replace it, although for many glass breaks this will be the part.
The screen that was broken took a while to pry off the phone, with the help of a mobile screen remover kit which I would highly reccomend buying for this repair, whilst the screen was being removed it did crack a few more times flinging bits of glass into the air, so maybe eye protectors?
After the screen was off there is a black adhesive that may still be slightly attached, this is what keeps the screen held down, keep it, unless you will be buying more adhesive tape then buy the 1mm tape for sticking the new screen down.
Position the buttons correctly, push down the adhesive tape and place the new screen on, the first time i did this the touch screen did not work, just re apply the screen until it works again and there you go, you have repaired a phone that some people may charge up to £60 or more to do.. for about £20 :)