pour a little bit of vegetable oil into your son's ear to grease the passage.
in hardware stores, they sell a little gadget called a "tri-ceps (or three claw) parts retriever" or simply "parts holder" that looks like a pen. Some have 4 claws. When you press down on the top of it (the "clicker") three little wire jaws emerge that will grasp an object. They cost about $5.
get one of these, and practice a bit on a few kernals of corn on your kitchen table to get the feel of it.
then use the tri-ceps to extract the kernel from your boys ear.
Nuke the extracted kernel in the microwave on high for about 15 seconds until it pops, and offer it to him as a snack. Kids dig gross.
Print this and take it to the hardware store with you.