IBM ThinkCentre 8105 Hardware Replacement Manual page 17

9. Remove the heat sink 1 from the system board by pivoting the lever 2
securing the heat sink until it is fully in the up position. Carefully lift the heat
sink off of the system board.
Note: Place the heat sink on its side on a clean, flat surface so the thermal
interface on the bottom of the heat sink does not touch the surface and
become contaminated.
10. Use the handle at the rear of the system board to pull the system board and
tray out the rear of the chassis.
11. Place the failing system board next to the new system board on a clean, flat
surface.
Chapter 2. Replacing hardware
9