Oracle X5-4 Service Manual page 187

See "Prepare the Server for Cold Service" on page
Identify the failed CPU.
2.
See "Locate a Failed Memory Riser Card, DIMM, or CPU" on page
3. Remove the two memory riser cards associated with the failed CPU.
4. Remove the heatsink:
a. Unscrew the four Phillips screws from the heatsink.
Turn the screws alternately one and one half turns until they are fully removed.
A thermal compound applied to the top of the CPU facilitates heat transfer to the heatsink
and acts as an adhesive.
Remove a Heatsink and CPU (FRU)
94.
86.
Servicing FRU Components 187