Dell H815DW User Manual page 486

6 Remove the jammed paper from the regi roll.
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.
8 Insert the MPF into the printer, push until it stops, and close the MPF.
486
Clearing Jams