I removed the top half of the case which revealed the four screws holding the lamp assembly in place. After removing the lamp assembly I can now see the four screws that hold the filter assembly in place. It appears as though some sort of grease or flux might have dripped down onto what must be the UV filter. Beneath the UV filter is another piece of glass (diffusion?). It looks corrugated but maybe that's the shutter that I'm seeing (see third picture). I can see how I'm going to get at the broken glass. However, the very bottom piece of glass is being held in place from below. It is intact but covered with this sticky stuff. It looks like I'll have to access it from behind the shutter. I can't figure out how to manually open the shutter. Also, any idea as to where I might find a replacement UV filter?