Canon MX920 Series Online Manual page 86

How to Detach / Attach the Disc Tray
Detaching the disc tray
Slide the disc tray to the side on the back of the cassette (upper) and raise it to detach.
Important
Be sure to remove all orange shipping tapes on the disc tray.
Attaching the disc tray
Align the holes of the disc tray with the hooks on the back of the cassette (upper) and slide it to attach.
Important
Be sure to align each hole of the disc tray with its corresponding hook on the back of the cassette
(upper). If the disc tray is not attached properly, the disc tray may be damaged during insertion of the
cassette (upper) into the machine.