3.While holding the Duplex Unit in both hands, align the edges on the unit with the guide rails in the printer.
cCaution:
Do not touch the areas specified on the caution labels inside the rear cover. If the printer has been in use, these areas can be very hot.
4.Slowly tilt it and slide it into the printer until it clicks as shown in the illustration below. Do not force the unit into the printer, as it is designed to join smoothly.
5.Close the rear cover of the printer.
6.Turn the printer on when you finish installing the option.
24Installing the Options