Apple PC Serial and Parallel Card - Manual (Page 3)

Opening the computer
1 Shut down the computer and disconnect all cables from the computer, except for the
power cord.
Leave the computer plugged in for now, to ground it and protect its
components from static electricity damage.
2 Remove the three screws as shown from the back of the cover.
3 Position your hands on the unit as shown and slide the cover back.
Firmly grasp the back of the computer and push in on the rear panel with your
fingertips while sliding the top cover back about a quarter of an inch with your thumbs.
Remove these three screws.
3 Installing the Card in a Power Macintosh 4400 or 7220