you can open headlights really easily. We do it often (celicas mostly) to paint the trim areas to match the body color. Pop the stripped down headlamp assembly into the oven, at 250 or 300 for a few minutes. PUT ON GLOVES. The clear lens will pull away. If you're careful, the goo (urethane) will remain pretty much on the edges and you'll have plenty to reheat and make a good seal. In the shop, we used to do this with a heat gun... not nearly so easy and much more ouchy. Just buff out the inner surface as you would the outer. Wayne