This Page Will Give You A Brief Overview Of Refilling The Canon 600 Series Printers

First off you need to seal the vent and ink exit holes on the cartridge.
A modification must be made in order to gain access to the cartridge. There is a steel ball on the bottom which is knocked through for refilling.
After knocking the ball through, simply use the syringe to fill the cartridge to the proper level.
Install the provided cartridge plug after filling the cartridge

Thats it! Remove the tape and you are ready to go!
Always check to make sure that the cartridge does not leak before installing!