Open the front cover.
Lift to unlock the drum unit lock lever.
Pull out the drum unit using its handle.
If you cannot pull out the drum unit, push the drum unit handle once before pulling it out.
Hold the upper drum stay, and remove the drum unit from the machine.
Be careful not drop the drum unit.
Set the color drum unit on the guide rail.
Push in the drum unit until it locks into place.
Lower the drum unit lock lever.
Close the front cover.
Make sure that the open cover/unit indicator () goes off, and that the color drum indicator on the panel display lights up.