Position your wrench in one of the screw holes and start to unscrew each bolt.

IMPORTANT: You must unscrew each screw an equal amount so you are removing the heatsink vertically and not at an angle. You could accidentally damage many of the components underneath the heatsink if you are not careful.

It may help to count off a number of turns as you're going to ensure that you apply even pressure in removing the heatsink.

I sharpied a line onto the one side of the handle of my hex key so I could more easily keep track of revolution count.

It took me about 17 turns on each screw to fully disconnect it, but your count may vary.

The screws are captive to the heatsink, so do not worry about removing them from the block.

You should hear a click as the screw pops out of the socket, as the screws are spring loaded.