Oki MC853 User Manual page 666

10.
While pressing the right arm (3) on the MP tray (2) inward, slightly
lift the MP tray (2) and hook the tab (4).
Note
Closing the MP tray without putting the tab back in place may crack the paper set cover.
Be sure to put it back in place.
11.
In the same manner, while pressing the left arm (3) on the MP tray
(2) inward, slightly lift the MP tray (2) and hook the tab.
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