Ok, here is a basic idea of how to get the headlight apart, I in no way would consider this to be a proper method of repairing the headlight lens, but to my knowledge there is no other way to open the headlights up. I hack up classic cars for a living so I think nothing of doing the same to my BMW's, but I understand a lot of people would cringe at the thought of going at their car with a dremel tool. I had taken apart the headlights on my e60 to remove the reflector ( same design ) and never had any condensation issues so I felt comfortable doing these.
-Once you get the headlights out there are 4 sliver retaining clips you need to pop off. Also there are 2 small torx screws that have to come out (pic1)
-The clear lens fits inside the black housing, the housing covers the part where the lens is sealed on so you are going to need to remove the part covering the seal to get access to it (pic2)
-I used my dremel with a cut off wheel to cut the lip on the plastic housing being carefull not to cut the clear lens under it (pic3)
- Once I cut around the whole headlight I started to dig up the plastic lip to get access to the seal (pic4)
-Now the hard part... with a sharp screwdriver and a box cutter handy I started to pry in between the lens and the housing breaking apart the seal all around the light. This is not easy and very time consuming. It would not take much pressure to crack the lens so you have to be paitent. the seal seems to have the consistancy of tire rubber and heat does not phase it so your pretty much stuck prying at it and cutting it with a razor a half an inch at a time. (pic 5&6)
-Once I went all the way around it I was able to pull it apart with my hands (pic7&8)
-For those of you wondering, I left the amber reflector alone on purpose because my car needs a little color, but the silver bezel on the headlight ring is actually painted on to the reflector so you can't just pop it out, you would have to paint just the orange part black (pic9).
- I washed the clear lens out with dish soap and water which did not get that film off, so I used some 3M liquid rubbing compound and a microfiber cloth to polish it off and it worked great.
-I used a gasket sealer called the right stuff made by permatex, (you can get it at Autozone) to basically glue the lens back on. I put a thick bead all aroung the black housing and pressed the lens back on. I also used blue tape to strap it together tight while it cured. (pic10)
The downside to this is that where the black lip you cut off was, now has beads of black silicone. The only time you can see any of this is if the hood is up and your looking at the backing of the headlight. Everyone can see the foggy headlights so I think it a pretty fair trade off... hope this helps, if anyone has any questions feel free to ask.