The heatgun repair is pretty easy to do. Just go REALLY slow, make sure to take your time doing it. Meaning, gradually apply and remove heat, and leave the maximum heat (at least 500 degrees F, no more than about 900) on there for at least five minutes (I do ten minutes). Make sure you carefully remove the yellow pad thing first, and don't touch anything until it's completely cool again, or you could ruin stuff.
When you're reassembling, it often helps as an extra bit of insurance to install a 1-2mm tall shim to keep pressure on the video chip. I use a replacement rubber stick-on foot thing (sold in packs at Wal-Mart and other places) and apply it directly to the metal shield after it's back in place before I put the bottom back on. It makes the bottom bulge slightly (I say 1-2mm because the bulge would be worse with anything bigger), but it does the job.
I've done four of these, and only killed one (I was impatient and angry, so I had the gun on max heat and applied it directly to the board). Popcorn'd it good - the motherboard started to separate from itself, bubbling up and doing crazy things. It never worked again. The other ones are still good, since I was patient and thorough. So yeah. SLOW.
