IBM THINKCENTRE 8141 - Manual (Page 19)

10. Lower the microprocessor retainer 3 and then lower the lever 2 to secure
the retainer. Make sure the lever is securely locked into position.
Note: If you are replacing the system board, a piece of black plastic will cover
the microprocessor retainer. When you lock the microprocessor in position,
remove the cover.
11. Place the new heat sink 2 into position and lower the lever 1 to secure the
heat sink.
Note: If you are only replacing a system board, install and secure the original
heat sink on the microprocessor.
12. If you are replacing the system board, continue at Removing and replacing the
system board at step 9 on page 6. If you are replacing a failing microprocessor,
continue at step 13 on page 12.
Replacing customer replaceable units (CRUs) 11