There seems to be a *huge* variety of the serviceability of laptops these days... I had a couple recently where the CPU cooler was choked with dust and the fan running poorly. On one (IIRC a stinkpad) you had the have the whole thing to bits in order to get at the right side of the motherboard. On the other (a dell I think) you could take a flap off the bottom, release 4 screws and the whole cooler assembly and heatpipes etc just lifted clear.