Dell H815DW User Manual page 457

2 Hold the both ends of the new retard roller, and attach it by sliding the two axles of the retard roller into the holes
on tray1.
NOTE:
Be careful not to touch the rubber rollers.
3 While pressing the lock lever on tray1 slightly to the right, press down the retard roller until it clicks, and then
release the lock lever.
4 Load paper in tray1, and then insert the tray into the printer and push until it stops.
457
Maintaining Your Printer