Dell DSS 2500 Owner's Manual page 118

Figure 57. Applying thermal grease on the top of the processor
1 processor
3 thermal grease syringe
3 Place the heat sink on the processor.
4 To install a heat sink of up to 135 W, perform the following steps.
a Tighten one of the screws to secure the heat sink to the system board.
b Tighten the screw diagonally opposite to the first screw that you tightened.
NOTE: Do not over-tighten the heat sink retention screws when installing the heat sink. To prevent over-tightening,
tighten the retention screw until resistance is felt. The screw tension should be not more than 6 in-lb (6.9 cm-kg).
c Repeat the procedure for the remaining screws.
118 Installing and removing system components
2 thermal grease