Here is what you need:
Two pop cans
Tin snips
A metal file
Gasket glue
A pair of needle nose pliers
A punch and small hammer
A sharpie
1 penny
a small handful of attic insulation
This gets the can out of the way so you can cut on the line.
Within the penny's cirle punch 5 small holes.
then punch holes carefully.
File off sharp edges.
Light and slide the penny over the fill holes in
the center.
Be safe!
Clayton