large can.
remove both the top only from one of the smaller cans and then removed both the top and bottom from the remaining third small can.
using the small can with both the top and the bottom exposed, slide it into the hole in the #10 can so it sits half-way inside. this will be a very snug fit, you will have to push hard, but do not use the hammer, it will damage what will be used as the feed chute on the rocket stove.
now, remove the feed chute can, pulling firmly yet gently, and trace the outline of the can’s opening onto the side of the second small can.
the 