How should I install the toner cartridge in the Canon MF1643iF II?

After placing the cartridge, shake it 5 to 6 times as shown in the manual to evenly distribute the toner inside before completing installation. The Photosensitive Drum must be protected from light whenever the Cartridge Cover is opened, so be sure to remove the cartridge carefully. Cover the Photosensitive Drum with 5 or more sheets of paper to block light and do not place the cartridge near direct sunlight. (Pages 16–17)