When a message is displayed prompting you to replace the ink cartridge, select How To and then view the animations displayed on the control panel to learn how to replace the ink cartridge.
The amount of remaining ink displayed on the control panel is the total amount of remaining ink in the sub tank, where ink is stored temporarily before supplying it to the print head in the printer and the ink cartridge. If you remove the ink cartridge once it has been installed in the printer and install it in another printer, the amount of remaining ink may not be displayed correctly.