A:Answer Unlike the cartridge, the drum is already in the unit, you do not get to install it. Install the toner and enjoy it working. Once the printer is out of toner, order another cartridge, the high yield one preferably, which will last for about 2500 pages. When you approach the 12000 of printed pages mark, you will have to replace the drum unit. By the time your printer will most likely already start dropping in the printing quality, that's when you should replace the drum.
