6.Lower the new cartridge down into the holder. Make sure the tabs rest on the hooks in back.
Hooks
Caution: Don’t place the cartridge tabs under the hooks; you may damage the clamp when you close it.
7.Press down firmly on the ink cartridge clamp until it snaps in place.
8.If you need to replace the other ink cartridge, repeat steps 3 through 7 before continuing with step 9.
9.Close the printer cover and press the 
ink button. The printer begins charging the ink delivery system.
80 Maintaining Your Printer