We now have the 7970 in two pieces; the PCB and the heatsink. Notice that one of the thermal pads that cool the memory chips has remained on the PCB - this can be peeled off by hand (assuming your hands are cleaned with soap and are oil-free) and attached to the appropriate place on the heatsink. Try not to lose or damage the thermal pads; you'll have to buy a replacement. PCCG stock them
as an example.