HPE ProLiant XL250a Gen9 Maintenance And Service Manual page 72

Disconnect the intra-tray signal cable from the system board.
17.
Remove all DIMMs ("DIMMs" on page 48).
18.
Remove all heatsinks ("Heatsink" on page 61).
19.
Remove all processors ("Processor" on page 65).
20.
Remove the failed system board.
21.
Removal and replacement procedures 72