How do I remove headlight condensation?

I had the problem and solved it by replacing the headlight with a new one. If your headlights are older, then a new one might provide better light anyway.

Remove the light socket and spread grease on the gasket

I drilled the holes several years ago. No more problems for me.

If the headlight is like my '03 Mountain Aire it is from a '02 Grand Marquis.

most headlights have a hole in the rear where the bulb goes in, you can remove the bulb and check to see if the gasket designed to fit the bulb is intact, that's the most likely place moisture is getting in. As others have said here, drilling holes in the headlamp assembly will only let in more moisture.

Had the same problem with my new Chevy Equinox. The back up lens had moisture ever since the purchase. I thought it would dry but finally removed it and tried to push a paper towel in thru the bulb hole but found that there was yet another clear wall between the bulb and the actual back up lens. I drilled tiny hole from the rear and it took about 4 hours for it to completely dry up. I waited a couple days and resealed the hole with a drop of silicone adhesive. Two weeks later, its still clear.

If you look at the bulbs, you will see gaskets that are supposed to seal the headlight assembly. The bulbs run hot enough to burn you in a few seconds and will burn off the condensation if turned on for a few minutes. Drilling holes will just allow condensation to get in to an area that is supposed to be sealed. Check the gaskets on the bulb assembly and make sure that it is functioning and turn on your headlights from time to time, even during the daytime hours, and you shouldn't have any problems.

Condensation or actual water filling it up? Suggestions posted for condensation but if actual water a drain hole will help but you're fixing a symptom and not the problem. Best to pull the assembly and try to seal it as best you can.

Drilling a hole will only serve to allow more water in. First you need to find where/how the moisture is getting in and seal that point up. Then remove the bulb to allow the current moisture to evaporate. Once dry and properly sealed you'll not have condensation issues. The leak could well be the rubber seal around the bulb it's self.

Drill small hole inoutside, let water drain. Remove bulb assembly from back, use hait dryer thru hole to finish drying. Repeat in 6months.