Oki C710n - Manual (Page 77)

77 – C710n User’s Guide
7. Remove the wrapping material and peel off the adhesive tape
from the underside of the cartridge.
8. Holding the cartridge by its top centre with the colored lever
to the right, lower it into the printer over the image drum
unit from which the old cartridge was removed.
9. Insert the left end of the cartridge into the top of the image
drum unit first, pushing it against the spring on the drum