Remove the three 8.4 mm #1 Phillips screws securing the heat sink to the logic board.

Don't lose the springs held under each of the screws.

Carefully remove the heat sink from the processor.

If the heat sink seems to be stuck, it may be helpful to gently pry it off the processor with a plastic spudger. Be careful not to break any surface mount components on the processor while prying.

Be sure to clean off the old thermal paste and apply a new layer before you reinstall the heat sink. We have a guide that makes it easy.