Compaq 247320-003 - Deskpro 4000 - 5166 Model 2500/CDS Reference Manual page 102

3. Remove the screw at the side of the expansion slot, then
remove the expansion slot cover from the slot as illustrated.
To install an expansion slot cover, follow these steps:
1. Slide the expansion slot cover into place over the slot
opening.
2. Install the screw at the side of the expansion slot to secure
the slot cover.
To install a PCI or ISA expansion board, complete the following
steps:
1. Remove the expansion board cage from the computer
chassis.
2. Remove the expansion slot cover.