Canon PIXMA iP5300 Service Manual page 22

(3) Front door removal
Open the paper output tray, and extend the output tray extension.
By bending the front door on both sides as shown in the photo below, the front door can be removed easily.
(4) Printer unit removal
The printer unit is fastened to the bottom case with 5 screws.
To remove the screw beneath the carriage unit in the home position, unlock the carriage unit first as follows:
(i) Unlock the carriage unit.
Rotate the gear (indicated by the red square) toward the rear side of the printer 2 or 3 times. The carriage will
be unlocked.