Step 1: Materials
Peltier Unit (Available from Ebay)
AC Adapter (7.5 Volts works nice)
Step 2: Cut Hole!
Cut a hole in the bottom of the box the size of the heatsink, and one in the side, as big as you want the door to be!
Step 3: Attach Heatsink
Attach the heatsink to the petier unit, the hot side will touch the heatsink. Then push the wires and switch inside.
Step 4: Finishing Touches
Put a piece of scrap metal on top of the peltier unit, put your drink on top, turn it on!