Tinkering with electronic is my hobby (I used to have a small business fixing radios, TVs, VCRs, and designed and constructed 144 MHz radios for fun. So I open and look inside every piece of hardware I own at some point (to hell with warranties). I understand that you are in dire need to have your laptop fixed... but if you can do it officially (on warranty), do it that way. What worked for me may not work for you.
Ever since I mentioned that going back to earlier ATI drivers helped, I've found two more "offenders": atheros drivers (I replaced Intel 2915 with Wistron CM9 Wi-Fi based on Atheros chipset, much much better but you have to find drivers that work reliably) and some remnants of latest Audigy 2 ZS notebook beta driver (gotta stick with original drivers from CD).
Now back to disassembling. On the back of laptop there is a screw that's holding the keyboard (right above the memory compartment). Unscrew it. Now you can open display and remove keyboard. There are to latches near the top left and right corners of keyboard. You push latches up (towards display to sink them in case) and pull top of keyboard carefully. Keyboard is connected to the main board so be careful not to tear the ribbon. To unplug it, you need to shift up the latch on the connector on main board and it will release the ribbon. Actually, it's quite well illustrated in this thread:http://www.notebookforums.com/showthread.php?t=106939
It also explains the rest. There will be a lot of screws on your desk. Keep 'em organized.
To get to CPU and GPU you need to unscrew main board (what you want to get to is underneath). The screws to undo are marked with white arrows on the board (4 of them if I rememeber correctly). Disconect some wires at HD and at the front on the left before pulling the board. Also, at this point you want antenna disconnected from Wi-Fi card as the cable goes through the hole in main board. You want it pulled out. Also, be careful with the ribbon that connects to touchpad. I could not figure out the latch on the connector so plugging it back in when reassembling was a bit tricky.
To remove heatpipe assembly unscrew 2 screws at the ATI chipset (one end of the assembly), 4 at the CPU (middle) and 3 (I think) at the fan. I kept the fan attached to heatpipe.
That's roughly it. Keep track of screws: some are just very slightly different from others in the batch, you don't want to have problems when putting it all back together.
I don't want to disassemble this laptop ever again. For reference, I disassembled TM8003 completely 3 times, easily.
Whew, that was one of my longest posts....