Canon imageRUNNER ADVANCE C9075S PRO Operating Information Manual page 253

Squeeze the lever, as shown below. Without releasing the lever, slide the outer size change
2.
plate and inner size change plate until they do not catch onto the paper you are setting.
Load the desired paper until approximately 10 mm (3/8") in height. Slide the outer size
3.
change plate and inner size change plate to align them with the desired paper size.
If you use a paper whose parallel edge to the feeding direction is longer than 457.2
mm/18", slide the paper holder plate to the right edge, press the button on the paper
holder plate, then fold down the paper holder plate.
②
If the paper holder plate is folded down, proceed to step 6.
①
Adjust the media size for the paper module
Chapter 9 - Paper, toner, and staples 253