Make sure that the power is turned on, and open the Paper Output Tray.
Lift the Scanning Unit (Cover), then hold it open with the Scanning Unit Support
The Cartridge Holder moves to the replacement position.
Do not touch the Cartridge Holder until it stops completely.
Remove the empty Cartridge
Take a new Cartridge out of its package and remove the orange protective tape gently.
This was copied and pasted from a free down load from the canon website. Any problems just go google your model # and go to Canon's website and on the front page click manuals. Good luck.