Lenovo ThinkCentre 3656 Hardware Maintenance Manual page 133

10. Rotate handle 1 to release the heat sink clamp and then disengage the
clamp from the plastic retention bracket.
11. Lift the heat sink and fan assembly off the failing system board. Place the heat
sink on its side so that the thermal grease does not come in contact with
anything.
Note: You might have to gently twist the heat sink to free it from the
microprocessor.
12. Remove the retention module from the rear of the failing system board and
install it in the same position on the new system board.
13. To release the microprocessor 2 from the system board socket, lift the small
handle 1 .
Chapter 9. Replacing FRUs - Rocky computers
127