Lenovo THINKCENTRE 6019 - Manual (Page 109)

9. Lower the microprocessor retainer 3 and then lower the lever 1 to secure
the retainer. Make sure the lever is securely locked into position.
10. Place the heat sink into position and lower the lever to secure the heat sink.
11. Go to “Completing the FRU replacement” on page 112.
Chapter 8. Replacing FRUs - Desktop computers 103