I bought a late 2009 iMac off of craigslist four days ago for a CRAZY price, the reason he sold it to me so low was because over half the screen was covered in a grey cloud that only showed up when it was on a white screen. After following this operation I now have a perfectly fine iMac for $250. Come up! Thank you guys! I ran into little to no difficulties, except the first time I did it I trapped a single hair in there that I knew would just drive me insane but after the second time it's now perfect.