HP ProLiant DL160 Gen8 Server - Manual (Page 55)

Hardware options installation 55
9. Press and hold the processor retaining bracket in place, and then close each processor locking lever.
Press only in the area indicated on the processor retaining bracket.
10. Remove the thermal interface protective cover from the heatsink.
11. Remove the adhesive tape from the slot, and then install the heatsink.
a. Using the guide pin on the processor backplate, position the heatsink.
b. Tighten one pair of diagonally opposite screws halfway, and then tighten the other pair of screws.