Lenovo ThinkCentre A61 Hardware Maintenance Manual page 99

6. Carefully take note of the location of all cable connections on the system
board and disconnect all cables. See "Locating parts on the system board" on
page 89.
7. Remove the screws that secure the system board to the chassis.
8. Lift the system board out of the chassis.
9. Remove the memory modules from the failing system board and install them
in the same location on the new system board.
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.
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.
Chapter 8. Replacing FRUs - Tower Computers
93