Oki C9300dn User Manual page 154

Gently push the coloured lever (5) forward until it stops. This
9.
releases the toner into the image drum.
Gently wipe the LED head surface with LED lens cleaner or a
10.
soft tissue.
Do not use methyl alcohol or other solvents on the LED head otherwise
damage to the lens surface will occur.
CAUTION!
MAINTENANCE > 143