rub the AS5 into the heatsink with something plastic, to fill all the imperfections. Then wipe away with paper tower. Then apply a thin coat to the CPU core. The AS guide says as thin as 1/300 the thickness of paper. GL with that. If you have been using the heatsink for a while, and see big scratches, then use some 800 grit sandpaper, and use it for 45mins while watching tv or something.