There is another way to do it as well, if you have access to a plasma cutter. Being very aware of your angle (so as not to burn through the outside of the can) run the cutter around the tip of your can, cutting out the endcaps and all of the guts you can easily reach. Break loose any slag with a screw driver and pull as much out as you can with needle-nose vise-grips. Clean up the edges of your endcaps with a dremel and you are good to go. A friend and I both did this to ours. I loved the sound, so left it as it was, but my friend thought it was a bit loud for his taste, so he tacked two opposing ears with holes in them inside the tips and mounted what basically looked like large washers to them with small screws so they were removable. Looked great and sounded very clean. To hollow mine out and pretty the edges up it took about 15min per can.