The blade used a section of the break away blades for a utility knife. Use the back side and not the blade side. It is less likely to break easily. One tool is used to drag along the side to put a slit into the plastic sheath to make it easy to peel apart. The other is to cut around the sheath to create a point to stop the peeling of the sheath. As for the screw to keep the blade in place, I had some old 3 mm wide short screws. You might find something that works better.