At WV-STOC, I needed to replace both ST110 headlight bulbs, as the second low-beam went out. I took off the windshield, trim, etc., so I could see the headlight housing from above. With help, I got the old bulbs, H4s with adapter rings, out, but couldn't get the new LED plates to seat and get the bail wires latched.
I finally concluded that I had to remove the headlight housing to get everything installed. I looked in the shop manuals I brought in the car, Honda and Clymer, and read what needed to be removed to get the housing out. I then decided there was no way I was gong to do all that, and tried again until it got dark.
The next morning, I tried again, finally deciding I had to take the housing out, deciding I was not going to take the housing out, trying again, and back and forth until I decided to try to take it out without removing everything the manuals said to. So, I brought a bar chair out of the cabin and started to open up the nose.
I removed as few fasteners as I could and managed to separate the nose of the fairing just enough to get the housing out. With it sitting between my knees, I was able to see that both bail wires and one latch clip needed to be tweaked for full engagement, and to let the wires pass as I twisted the bulbs into the plates.
With the bulbs in place, I tried them to make sure they worked. I noticed that the engine needed to be running for them to properly switch between low and high. Then I reversed the disassembly, got everything back together, and I only had two screws left over! I know where they go, and I can put them back in later.
I haven gone for a ride in the dark yet.