HP ProLiant DL580 G4 Server - Manual (Page 66)

Expansion board options 66
4. Unlock the retaining clip (for full-length expansion boards).
5. Lift the latch, and remove the board from the server.
CAUTION: To prevent improper cooling and thermal damage, do not operate the server unless
all expansion slots have either an expansion slot cover or an expansion board installed.
To replace the component, reverse the removal procedure.