For replacing a cartridge, remove the top cover and battery. Please ensure to open the bottom latch before pulling out the cartridge. Only when it is open, the cartridge can be removed. Remove film from new cartridge and insert it into your e-mark electronic stamp untill it snaps into place. Close the bottom latch, reassemble the battery and top cover and then press the ON switch to configure the new cartridge automatically. Each cartridge last approximately 5,000 full-color imprints and can be purchased exclusively through our website! Please watch the video “How to change a cartridge” below for further details and a full demonstration. If you have any questions, please contact us. Our customer service representatives will be happy to assist you with any inquiries!