Hi guys, I know its a few years to late but I thought ide add my story as it may help someone down the line.
Now what I've done is taken what I wrote on another thread and copied certain parts in here that are relevent to this.
Ive got an 2002 S3 8L and strangely when I purchased it, one headlamp looked brand new, and the other had the cloudy/rough deterioration to it.
So today I decided to clear it up, and I followed this link: 3 Ways to Repair Oxidized Cloudy Headlights with a Headlight Cleaner
I actually found is very straight forward to remove the bumber, as there are 4 plastic lugs under the bonnet which following what I had read on here, screwing a small hook into them. In order to pull them out worked a treat.
now when I got to the light, I realised that the lense could be unclipped from the light unit, which made my life easier as I wouldn't have to faf around trying to get the whole light out which looked to be a pain as I couldn't even find one out of the two bottom screw locations.
Now regarding the lense, I found it took me a while to get through the sticky foam glue stuff which obviously acts as a sealant as well as to ensure the lense stays in place (as well as four clips)
Now i know its already been said but i will stress again as i wasnt told how delicate the chrome finish is on the inside of the lamp unit and on that little bit of plastic trim that comes off inside the lamp. So I decided to wipe the inside with a damp cloth and window cleaner to bring back the chrome look, and low and behold, it came off in my hand....the window cleaner literally dissolved it. Luckily I had only used it on the plastic trim piece and not the actual headlamp unit, as I can just purchase another or spray paint it...but I guesse it requires a very light touch otherwise it comes straight off.
Ive followed all the steps in the link I provided, which was wet n dry paper, polish, and a extremely good buff up with a electric buffer, and it made it much butter (i couldnt see all the diagonal lines on the lamp before and now they are there as clear as day) but its still not good enough as the drivers side one looks like new, which makes the car look uneven....
So I am going to buy a new lens for me light and if anyone is interested in the passenger side lens, let me know...
Conclusion: it can be done and you can take the lamp to bits, its tricky, requires lots of levers and patience and you have to break the seal.
Since posting my days work on a mother thread, someone told me to use a heat gun on the foam part which will release it easier. I'm assuming a fairly powerful hair dryer would do the same trick? As I don't have access to a heat gun.
moreover I never actually managed to get the whole light out (not that I tried that hard) but it would be nice to remove the whole thing.
does anyone know what I could use in place of the foam sealant as when I buy the new lens, ill want to seal it in there with something. I was thinking a kind of silicon gel?