There are only two corn cans in the game - both have to get destroyed.
The first one is really easy. You can find the can of corn in the miner's puzzle. The miner throws three objects at you (shovel, bucket and can of corn). Then, he throws dynamite at you. It suffices that he throws a dynamite at his own can of corn to get it destroyed (the can looks different and even the description says it's destroyed - that's how you can see that it worked).
Now, the other can is a bit more tricky. It is on the last puzzle on the lonely island. The can is behind that blue box all to the right (and also some crackers). You have to take that can and place it somewhere near the exploding barrels in the volcano, so that the explosion destroys the can of corn in the process.
The process of your destroyed cans of corn carries on over multiple playthroughs. So if you destroyed one can once you don't have to destroy it again.