When it is time to replace the staple cartridge, a message is displayed on the LCD screen. Follow the on-screen instructions to replace the cartridge.
The following is the code for the cartridge.
Staple Cartridge : C12C934911*
*Contains at least 1000 staples.
Do not remove the cartridge except to clear a staple jam or to replace it with a new one.
Do not open the part 
shown below.
