Oki C330 - Manual (Page 89)

89 – C330/C530 Replacing Consumables and Maintenance
7. Take the new image drum cartridge out of its packaging and
place it on the piece of paper where the old cartridge was
placed. Keep it the same way round as the old unit. Pack the
old cartridge inside the packaging material for disposal.
8. Place each of the toner cartridges in the new image drum
reversing the process used to remove them. Be sure to put
them in in the proper sequence. Slide the collars back to the
left to secured the cartridges in place. (It is not necessary to
fit a new toner cartridge at this time unless the remaining
toner level is very low.)