Oki MC160 User Manual page 260

2
Remove the tape affixed to the
rear cover.
3
If the locking pins are installed on the left and right side at the back of
Tray 2, remove them.
To remove a locking pin, turn it to either the left or the right so that its grip
is vertical, and then pull out the locking pin to remove it.
4
Prepare the duplex option.
10-10 Duplex Option