6Insert the left end of the cartridge in the image drum, placing the recess in the end of the cartridge under the
7Lower the right end of the toner cartridge, aligning the slot on the cartridge with the ridge in the image drum and push the blue lock lever toward the back of the printer until it stops.
8Clean the LED arrays: open the LED lens cleaner package supplied with the toner cartridge and use it to clean the LED arrays located on the underside of the cover.
9Close the cover, pressing down to lock it in place.