Uchida Of America Mini Paper Trimmer To release and replace cartridge, press button on the front of guide case and pull the rear of blade cartridge with the forefinger out of the guide case; Put new cartridge into guide case; Close the lid of guide case with a click sound To place the paper into the cutter, lift the cutting guide rail with the end stopper and place the paper; Close the cutting guide rail and press and slide guide case to cut paper To replace a worn cutting channel mat, lift the cutting guide rail and remove the worn mat Built-in storage compartment; convenience and space saving built-in storage compartment for safety blades on the back side of paper cutter Compact and lightweight