Compaq 247320-003 - Deskpro 4000 - 5166 Model 2500/CDS Reference Manual page 92

5. Grasp the expansion board cage by placing one hand on the
back lip of the cage and two fingers of the other hand in the
finger hole near the front of the cage .
6. Pull up and out to remove the expansion board cage.
7. Rest the removed expansion board cage upside down on
the power supply and drive cage.
The slide-out system board tray allows you to quickly remove
the system board, without using tools.
To remove the system board tray, follow these 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 and any external devices.
3. Disconnect the power cord from the power outlet.