Compaq 247320-003 - Deskpro 4000 - 5166 Model 2500/CDS Reference Manual page 153

To remove the power supply, complete the following steps:
!
1. If you have locked the Smart Cover Lock, use Computer
Setup to unlock the lock.
For more information about Computer Setup, refer to
Chapter 8, "Using Compaq Utilities."
2. Turn off the computer, disconnect the power cord from the
electrical outlet, then remove the side panel.
3. Disconnect the power connector from the system board and
from any drives or other peripherals.
Label each power connector, before disconnection, with
the connection location. After doing this, you can easily
reconnect power to the correct devices.