Apple Xserve (Early 2008) DIY Procedure for Enclosure - Manual (Page 133)

Xserve (Late 2006/Early 2008) Logic Board Replacement Instructions 23
Use the edge of the package that the alcohol wipe came in as a spatula to spread the 3.
thermal grease evenly over the entire top surface of the processor. Scrape off any excess
grease with the package edge, then discard the package.
Holding the processor by three corners only, keep the processor level as you place it into its 4.
holder on the logic board, being careful not to get any thermal grease on the contacts of
either the processor or its socket holder.