Dell C3765dnf Color Laser Printer - Manual (Page 485)

Maintaining Your Printer 483
3 Slightly pressing down the lock lever on tray1 to the right with one hand, raise the retard roller with the other hand.
4 Slide the retard roller to the left to remove it from tray1.
Installing a Retard Roller in Tray1
1 Slide the two axles of the retard roller into the holes on tray1.
2 Press down the retard roller until it snaps.