How to Install a Toner Cartridge in an HP LaserJet 1200 Series

Turn off the printer.
Flip the front toner door toward your body, exposing the printer cartridge. The toner door will release the cartridge. Slide it out of the compartment.
Remove the new cartridge from its package and shake it back and forth. Bend the tab on the cartridge's right side to release it and pull out the strip of tape from the cartridge.
Slide the cartridge into the toner compartment. It will snap in place. Close the toner door.