Carefully lift the heat sink off the logic board.
If the heat sink appears to be stuck to the logic board after removing all eight screws, it may be helpful to use a spudger to separate the two components.
When reinstalling your logic board, don't forget to apply a new layer of thermal paste to the face of each processor.
crwdns2944171:0crwdnd2944171:0crwdnd2944171:0crwdnd2944171:0crwdne2944171:0
crwdns2931507:0crwdne2931507:0
crwdns2931509:0crwdne2931509:0
crwdns2931511:0crwdne2931511:0
crwdns2931513:0crwdne2931513:0
crwdns2931515:0crwdne2931515:0
crwdns2931517:0crwdne2931517:0
crwdns2931519:0crwdne2931519:0
crwdns2931521:0crwdne2931521:0
crwdns2931523:0crwdne2931523:0
crwdns2931525:0crwdne2931525:0