Either watch a lame video, of continue reading.
Step 1: Wacha Wacha Gonna Need?
post 1982 pennies
wire & solder
Step 2: Prep the Pennies
Alternately I tried both belt sander and disk sander, excellent ways to burn your fingers, but not appreciably faster.
Step 3: The Electrolyte
Step 4: Assemble
Now start stacking coins and cardboard, with all the coins copper side up, stack them with a peice of soaked cardboard between, secure with a rubber band and attach the leads to a low current electrical device, the copper side is the positive. And Tool said "Let there be light".