Dell PowerEdge R900 - Manual (Page 102)

102 Installing System Components
2 Open the system. See "Removing the Top Cover" on page 60.
3 Remove the cooling shroud. See "Removing the Cooling Shroud" on
page 76.
NOTICE: When you remove the processor heat sink, the possibility exists that
the processor might adhere to the processor heat sink and be removed from
the socket. It is recommended that you remove the processor heat sink while
the processor is still warm.
NOTICE: Never remove the processor heat sink from a processor unless you
intend to remove the processor. The processor heat sink is necessary to
maintain proper thermal conditions.
4 While pressing firmly on the blue tab on the end of the heat-sink retention
clip, compress the sides of the retention clip together until the clip
disengages from the sides notches of the heat sink bracket, and then slide
the retention clip forward to release it from the back notches of the
bracket. See Figure 3-19.