Hold bottom of headlight ring, push up gently and the ring will be in your hand away from the headlight and headlight bucket. The top of the ring sits behind a small lip that you have to go up and out to clear.
Are you trying to get the light it self out or are you trying to remove the light and ring from the bucket on the bike?
If it's the light/ring from the bucket on the bike:
Remove two small screws that are on the sides of the BUCKET. Then pull slightly up.
If it's the light itself from the ring:
Remove the two adjustment screws that are next to the light. Look at the top on the inside. There is a retaining piece of bent copper colored metal that you need to take out. It is only about 2 inches long and bends with pressure. It will pop back into shape when you need to re-install.
I bought a glass replacement fixture with a 100/80W H4 bulb and I want to replace the stock light with the new fixture.
I can replace just the bulb and get by but eventually want the new fixture in the place of the stock.