I have learned a little more..
so let me try to walk you through this from a purely amateur's point of view.
First, it is wayyyy easier to do this if you jack (and support) the car and remove the tire.
On the fender lining, there is a "door" that gives you access to the lights from behind. There are actually 2 such doors--this is the higher one. Use a quarter or the like to turn the two thumbscrews, I think 90 degrees, that are on the outside end of the door. It then comes out by pulling two tabs on the inside end out of their slots.
Behind the door, the lights are sealed in a compartment that has a rounded, non-regular shaped metal cover. The cover is held on by a spring wire bail that extends from the upper outside to lower inside, slidig over center on two notches on the back of the cover. Put a common screwdriver under the bail, lift it away from the cap and down at each notch, then it rotates down mostly below the cover.
Then you have to maneuver the cover out of place. Takes lots of tries, but again much easier if the tire is gone. Pay attention to how you twisted it to get it out--you have to put it back.
Once the cover is off, the main thing in there is the headlight. But inside of the headlight, maybe just slightly higher than center, and with the back of it maybe 2" closer to the front of the car than the headlight, is the black plastic holderfor the halo light.
This is what stymied me the first time. I could see it, I could snake my hand on to it, no way I could figure how to get it out. Finally, with the tire gone, I could see two small torx headed (maybe #15) screws, one either side of the black plastic holder. I removed them with great fear thay would drop and be lost, but looking at the bracket where it sits next to my computer, I saw that it has arrows suggesting it can be rotated to "open" and "close."
I guess that two "wings" that are part of the structure of the holder slide under one edge of the head of the screws--can't see it, but the wings must have a slight incline so they add pressure as you twist. I have no idea whether this all should work w/o ever touching the screws, but I would guess so.
Per the arrows on the holder, clockwise is close and counterclockwise is open.
It was too late and I was too impatient when I tried to drill out slots either side of the bulb to actually pull the bulb out of the holder and replace only the bulb.In retrospect, I can see that the idea should be to destroy the bulb, breaking the glass and twisting the base to fold it in on itself to pull it out. With the bulb out of the holder, it is very obvious where you need to grind or file notches on the holder to put in a new bulb. The holder has the classic slot to push the bulb down, then twist slightly into place. Just has no place to slide the two little lugs past the plastic opening at the top.
Hope this helps. Call if you want to talk. 954-249-3246