head light replacment

So i got a headlight replaced on one side but the other is the original. I was wondering if anyone knew how to clean the foggy dirt off the old one to make it look brand new once again? same goes with the fog light the right side is brand new and the left is the old.

So, I started with this post, a great help: http://newbeetle.org/forums/2-0-liter-gas/9400-2-0-headlight-removal.html Wanted to add a few things. Dealer wanted $67.00 each to replace the lamps. The lamps were about $5.00 after tax at Kragen Subject NB is a 2005 2.0 liter. Everyone else...