Cheep-n-eezy; Get a panel of those muffin tins from the store;cut out a couple of 'em and poke a hole in the center of each one. Take the bulbs outta your taillights,wipe the inside of the lenses off really clean,or run 'em through the dishwasher.Slip the muffin tins over the light sockets and form 'em the best you can to the inside of the taillight housings. Put everything back together and wipe a little silicone grease over the gaskets to be sure no dirt can get inside.Wouldn't hurt to pack some sealant around the wiring at the point where the wires go into the housings.
Time spent-about half an hour. Money spent-about a buck.
Speed