!WARNING: I AM NOT RESPONSIBLE FOR YOU BEING DUMB. BE SAFE AND EXERCISE CAUTION
I will not show you how to make the stand for the cannon because I don't think most of you have a pair of skis lying around. I also dont believe you have a trumpet you can take the keys off of. I WILL encourage you to make your own stand. I Just happend to live near a junk yard full of this stuff.
Step 1: Finding a bullet casing (or two)
I say find a bullet casing or two because you might mess up and need to try again.