Dell H815DW User Manual page 461

5 Hold tray1 with both hands, and remove it from the printer.
6 Wipe the feed roller inside the printer with a cloth moistened with water.
MPF Feed Roller
Tray1 Feed Roller
7 Insert tray1 into the printer, and push until it stops.
NOTE:
Do not use excessive force on the tray. Doing so could damage the tray or the inside of the printer.
461
Maintaining Your Printer