Cleaned the inside of the mirror turning lamp lenses. Very simple, so I'll run through it very quickly here:
You'll need: T10 Torx driver (I used an actual driver, but it looks to have enough room to fit a bit-style driver in there), straight screwdriver, method for cleaning (I used detailing wipes)
Move the mirror assembly forward on the hinge, this will expose the Torx retaining screw underneath between the lens and the hinge mount. Remove the screw, be mindful as this thing is exposed to weather and may have suffered some corrosion. Tilt the lens forward and down from the front-facing portion; it may take a little bit to figure out how exactly it comes off.
Remove the bulb socket by turning the rubber part until it lines up with the four holes in the lens, and then pull it out. This will take a bit of effort as the rubber retaining the bulb from the inside is very thick, you'll see what I mean once you get it off, and it'll take as much effort to put it back in.
Using a screwdriver, remove the endcap. There is a slot on the bottom side for this purpose. Be careful and don't go nuts, this plastic has been exposed to the outdoors for a lot/all of its life. You may develop a very small hairline crack on the lens. If you want to reduce the risk, find a method to pop the retaining ball on the end cap out of its hole in the lens (look at the top side of the lens that meets the mirror, you'll see a circular hemisphere poking out, this holds it in).
I used cleaning wipes which made it difficult to reach deep inside and get the end of the lens properly, you can use this method (take the straight screwdriver and put the wipe on it to help reach the end easily) or you can just take them inside and wash them in the sink or with a hose or something. Allow to dry before starting reassembly.
Reassembly is the reverse of disassembly, however it is important to note that you only turn the bulb socket 45 degrees to seat it. If you turn the full 90 (where it feels like it locks), it's actually lined back up to remove again, just at a different angle. Since your lens is now clean, with proper light you should be able to see inside to make sure it's seated firmly. Be mindful of the wires as you're fitting it back in, and make sure the lens is completely seated when you're done by grabbing it and applying LIGHT twisting or pulling force; it should either barely move, or not move at all.