You're right, the one odd screw out front is the horizontal adjustment. So just the two screws on the side to pull the light out. Then the trim ring must be attached from inside, don't even need to bother with that, and definitely not the adjuster..Thought it was just the two to loosen the bucket and the 3rd (more forward pointing) is to adjust the lamp angle. There’s a spring and small plastic piece behind that. Nothing major just warning you so it doesn’t pop out on you. I made that mistake and it took me 15min to find that “thing” I dropped. I had no idea what I was looking for until I found it lol.
Here’s a pic when I upgraded my headlight bulb