7.Disconnect the fan cable from the system board connector labeled CPUFAN (1), and then loosen the four captive screws (2) that secure the heat sink to the system board tray.
CAUTION: Heat sink retaining screws should be removed in diagonally opposite pairs (as in an X) to even the downward forces on the processor. This is especially important as the pins on the socket are very fragile and any damage to them may require replacing the system board.
110 Chapter 5 Removal and replacement procedures – small form factor (SFF) chassis