I am new to this forum. I've got a 2003 735Li recently. I thought the headlights need some cleaning because it looks foggy inside. After many search of topics about cleaning the headlight. Seems there are only two options, either to go and get a new one or cut open the assembly, clean it, then glue it back.
Few days ago the right parking is gone and I have to remove the bumper and take it out to replace it. Just as I put it back and then I might have an idea. What if I remove the high beam bulb and squeeze a small piece of cloth and put a stick in try to clean inside bit by bit. As a result I can clean the high beam area and it do make difference but can't reach to the low beam. Just when I get frustrated, then I thought what if I stitch that cloth to form a small pocket and put a strong magnet in it then seal it. Squeeze it in and then use another magnet to guide the cloth cleaning from outside! I think it will work. And I am going to do it in a few days time. Once finished I will post the result and pictures as well.
I am not a native speaker of English and am sorry for the poor writing!
So at last, I did it in the car park. For me its a 3hrs DIY job. I can tell you guys you will be amazed by the result. Without spending much but a few dollars(HKD) of the lint-free cloth. In my own experience, there is no way you can pull the headlight out without remove the bumper! Once you find out all the hidden screws its very easy to take it out. I also replace the holder for the side of the bumper(51118223247), it gets brittle after all the years.
I think this DIY not only apply to BMW models(except E46 which the plastic cover id detachable), but all vehicle with plastic headlight cover. I took some pictures while DIYing, hope you guys find it useful!