As far as moisture build up goes you can remove the entire assembly and aim a hair dryer inside the holes where the lamps go, then put it all back together. However if you're aiming to get rid of the coloration on the lens that is near impossible because the plastic is faded/warped
To clean the inside headlight lens on a ford ranger just simply remove the cap and clean.
Sell it!
The same way you clean the outside. Tip: Remove the headlight first to get access to the inside. Pretty simple, should only take 2 or 3 beers.
drain stopped up locate the drain tube on the passenger side at the firewall and use compressed air or a wire to clean it out, water should run out of it.
Are you sure the dirt is on the inside? Most of the time the dirt is on the outside and only looks like its on the inside. You can clean the outside with Crystalenz. This stuff works really well, for more info see the website www.crystalenz.com. If you have water on the inside, you can drill a small hole (1/8th) or smaller on the lower side of the lens, and it will clear up over time.
I doubt it as the headlights are sealed and most don't come apart.
Avalon Rare Metals's motto is 'Materials for Clean Technology'.
you have to take the front bumper off from underneath your car to get to the lights.
put the headlight in the oven at about 215 degrees for about 5 min then pull the lens off the housing, clean it then use some automotive glue and push the lens back in. look it up on YouTube very simple
Try using a carwax and a clean shop towel and scrub the lens surface like your polishing your car paint. It takes a while of rubbing but it worked in my 2003 corolla.
If the inside is dirty or cloudy it's probably because of a cracked headlight assembly. Unfortunately you can't really do much to clean it. I guess you could remove it, rinse it out with distilled water, blow it dry then put it back, but even that probably won't do much good. The reflective surface on the inside is very soft and will come off and/or scratch easily so don't touch it with anything.
are you sure the damage is to the inside of the lens, it may only be on the outside. Ever noticed moisture inside the lens? If not the cloudiness is just on the outside and that can easily be fixed check out The Headlight Solution for more information about clouy, foggy headlight lenses and how to repair / restore them like new. The sell headlight restoration kits through there websire at http://www.headlightsolution.net