6.Lift the heat sink from atop the processor and set it on its side to keep from contaminating the work area with thermal grease.
Figure 7-48 Removing the heat sink
When reinstalling the heat sink, make sure that its bottom has been cleaned with an alcohol wipe and fresh thermal grease has been applied to the top of the processor.
CAUTION: Heat sink retaining screws should be tightened in diagonally opposite pairs (as in an X) to evenly seat the heat sink on the processor to avoid damage that could require replacing the system board.
