Oki B720dn User Manual page 40

Do not touch any parts inside the printer.
2. Hold the drum/toner cartridge by the grip and pull it out slowly.
NOTE
To prevent the toner from dirtying the floor, lay a piece of paper on the floor
first before putting the drum/toner cartridge down.
3. Take the new drum/toner cartridge out of the packaging box and shake it 7 to 8
times as shown in the diagram.
NOTE
> If the toner is not evenly spread out, the print quality may be reduced.
Also, if you did not shake the drum/toner cartridge well, there may be
operating noise or the interior of the cartridge may be damaged during
operation.
> Do not touch the surface of the photosensitive drum.
CAUTION!
Daily Care > 40