Apple PC Compatibility Card (Installation) - Manual (Page 36)

Removing the video input card and the PCI port cover
If you have a video input card already installed, you need to remove
it temporarily to give yourself more room while you install the
PC Compatibility Card.
1 Unscrew the screw on the front of the vertical plate that holds the video input card in
place, and remove the card as shown. (You’ll reinstall the card later.)
Skip this step if there is not a video input card installed on your logic board.
Video input card If you have a video input card installed,
you will need to remove it to give yourself
room to install the PC Compatibility Card
in the lower PCI slot.
Video-in slot
Screw
36 Chapter 2