remove it from the slot, on the back there should be some clamps, uses a small screwdriver and then pop that off
(heatsink) thebn just use the lever next to it to pry it of.
if you can't find the clamps, you need to remove the plastic back off of it.
It seems that the heat sink it attached to the CPU by pins going through it. And it seems that the Heatsink it permidently latched in by a piece of metal.