Refill Canon Pixma CLI-8 und PGI-5-Cartridges: Step 1: Open the cartridge
Look at the pictures below. Use a 2-millimeter drill and start drilling at the exact position shown in the pictures.
Click on the pictures to see an enlarged version.
Be careful: Stop drilling as soon as the drill got through the plastic. If you don´t, the sponge might wrap around the drill, and you are in trouble.