Here is what you need to do to replace the drum unit on your printer:

1. Turn off the printer and make sure the power cord is disconnected.
2. Open the front cover.
3. Remove the drum unit from the printer.
4. Unpack the new drum unit and remove the packing materials.
5. Install the drum unit, making sure to fit each part into its respective place.
6. Close the front cover of the printer.
7. Connect the power cord and turn the printer back on.