Follow these simple steps to shotgun a beer:
1. Get a can of beer and hold it horizontally on a table. The reason is so that the air bubbles can come to the side of the can and not at the top of the can.
2. Position your hand very close to the bottom of the can and talk the can with your thumb, after which you can get any sharp object like a knife to puncture the can at the same spot, though you can still do this completely with your thumb.
3. Try to resize the hole and push any sharp part of the can inward so that it won't injure you.
4. Put your month on the can exactly where you have punctured it and place it vertically.
5. To allow the air to go into the can as you drink from it, use your dominant hand to pop the tab open. Then, start drinking the beer as fast as you can.