Cadillac 2000 Catera Owner's Manual page 167

You must first load the magazine with discs before you
can play a compact disc. Each of the 12 trays holds one
disc. Press the button on the back of the magazine and
pull gently on one of the trays. Load the trays from
bottom to top, placing a disc on the tray label side down.
If you load a disc label side up, the disc will not play
and an error will occur. Gently push the tray back into
the magazine slot. Repeat this procedure for loading up
to 12 discs in the magazine.
Once you have loaded the discs in the magazine, slide
open the door of the compact disc (CD) changer. Push
the magazine into the changer in the direction of the
arrow marked on top of the magazine.
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