This video is how to open a metal can with the corner of a knife. First, you must find a knife that has a ninety-degree angle where the corner is a sharp point. A cleaver, like the one shown in the video, type of knife would be best. You use the corner to puncture the can and continue puncturing it as you rotate the can. Make sure to tilt the knife outwards after you puncture. Puncture successively and simultaneously rotate the can so that each puncture mark starts where the last one left off. Make sure to rotate the corner of the knife to elongate the puncture mark. This will open the can.