Here is my experience with removing the headlight lens and why. I decided to make a new thread dedicated just to this as it is a process!
1. Don't do this unless you absolutely have to
2. It is not an easy job and if not REALLY careful you will destroy the housing lens or both
3. This worked for me, but not responsible if #2 happens

With that said I took a picture of everything I used to get this apart
Must haves
Panel clip pliers
very long and thin flat head screw driver
shorter thin flat head screw driver
gloves
Oven or heat gun
razor blade very sharp
Nice to have
pry bars
Highly suggested
drink of choice (many)
Why did I do this
my wiring inside was crumbling and I have removed headlight lenses before so thought this would be the same procedure. WRONG. I started the normal process and made just enough progress where I knew I broke the gasket so had to complete the process.

Why is it not like other headlights?

Other headlights use butyl rubber to seal and it becomes workable somewhere between 170 and 240 depending on your method of lens removal. VAG on this headlight used what looks like windshield sealant which is an air cure urethane. Urethane has a MUCH higher working temperature so it will not become soft or release easily at a temperature that won't destroy your light.

Steps I took
1. remove as much metal as you can and take off access doors
2. preheat your oven to 240 (it doesn't matter for the urethane, but makes the first step much easier
3. once the oven is preheated place the light on the very bottom rack for 15-20 minutes. This will get the housing very soft and workable.
4. remove the housing using the gloves and quickly use the panel clip pliers, screwdriver, magic wand to work a corner open and basically peal the plastic back so that you can insert the screw driver on both the top and bottom side of the lens to act as a wedge to separate the adhesive from the lens and body. You will use a combination of panel pliers, long screw driver, short screw driver and pry bars while using a razor blade to cut as much free as I could.
5. Once you get a foothold you don't need to heat the housing again, just continue to work around the lens freeing from the housing and adhesive. This is a delicate balance of going just enough ape **** and to much and breaking the lens. You will mess up the light housing, but that is ok we are going to reheat it once this is all done to get it mostly back into shape. Be VERY carful as you do this for a few reason.

1. you can break the housing or the lens
2. It is really easy to let something slip and scratch up the chrome

6. Continue to work and cuss. I suggest taking a break contemplate why does Audi really hate their customers working on their own cars this much. Have a beer.
7. continue prying and pulling and cajoling until you get the lens free. It took me 45 minutes of this
8. Yeah the lens is free have a beer
9. to clean up the adhesive I used both a wonder wheel and the rasor blade to clean up as much as I could
10. insert the housing back into the oven for another 20 minutes at 240. When you pull it out use your hands, smooth clamps excetra to shape the channel of the housing back into shape. Interior is much more important than exterior as we will clamp the exterior when we reassemble the housing to the lens. I would have a beer while you wait for the housing to heat up
11. Let everything cool off and now you are ready to clean up the light housing, and try to remember why you took it apart in the first place
12. Sit back and bask in your glory of accomplishment or cry that you destroyed the lens or housing. Have another beer either way.

Tools used

I started on a bottom corner. This is the plastic after I reheated in and reformed it. Will do a more formal job, I just wanted to make sure it would reform.

I will follow up with reassembly using butyl but am waiting on some connector pins to complete the wiring which is why I started this in the first place. Sorry I didn't take more pictures, but was in the throws of battle. If god forbid I do the other one I will get some more of exact method used to separate.