Canon MX300 printer, need help installing ink cartridge?

I'm trying to help my grandmother figure out her printer. We stuck the cartridge in the printer, but she thinks now it has to ';install'; itself in the printer. What exactly is installing; is it just putting the cartridge in the printer or is it more in-depth than that? Please help!Canon MX300 printer, need help installing ink cartridge?
I have some instructions for you:


1. Make sure the printer is on and paper is loaded in the tray.


2. Gently lower the print carriage access door at the front of the unit. Do not force it.


3. Press down on the print cartridge gently to release it. Pull it towards you and remove.


4. Take the new cartridge out of its packaging. Gently remove the plastic tape by pulling on the pink pull tab.


5. Slide the new print cartridge into the empty slot, and gently push forward until it clicks into place. If it does not click, do not force it. Remove it, and try again.


6. Close the print carriage access door. An alignment sheet will print to make sure everything is lining up.


Hope these help.