First on one can you want to remove the tab. And on that can mark 1 1/2 inches from the bottom. Then turn over that can and use the x-acto knife to score the bottom of the can. Then use pliers to punch out the bottom and take the pieces out. Now on the other can, mark 3/4 of an inch from the bottom.
Step 3: Cutting The Tops Off
Now on both cans cut the tops off. On one can use the scissors and cut along the marked line. On the other can, don't cut the metal that is in the middle of the can. Cut a small hole by the line and cut along the line.
Step 4: Making The Inside
Now use that piece of metal that is the middle of the can and cut a 4 cm strip out of it. Then make sure it fits snugly in the small cut out of the can. Then hold the 2 ends and mark a line on each side. Then cut half way and interlock both ends together.
Step 5: Making The Fuel Ports
Now at the bottom of your little strip cut little squares out and fold the metal upwards.
Step 6: Assembly
Now cut a small rectangle into your small cut out. Then place your little strip into it and make sure the fuel ports are on the bottom. Then take your bigger cut out and place it on-top and push down. Make sure the top of the little strip does not bend outwards.
Step 7: Jets
Take your drill and 1/16 bit and drill 16 evenly spaced jet holes on the outside of the can. Don't push so hard that when you drill through it punctures the little strip.