Oracle X5-4 Service Manual page 188

Remove a Heatsink and CPU (FRU)
b. To remove the heatsink, break the seal created by the thermal compound by
slightly twisting the heatsink left and right while pulling it upward.
Do not allow the thermal compound to contaminate other components. Retain the heatsink.
You need to reuse it.
188 Oracle Server X5-4 Service Manual • December 2015