Hp 7400c haze on INSIDE of scanner glass

I figured this one out.

There is a language panel on the front (that tells you what each button does). The original instructions mentioned putting the panel on but not taking it off. If you use a small, thin screwdriver or thin, dull knife from underneath, you can work your way across the bottom edge, popping off the language panel. When you remove the panel you reveal three screws, one rather tiny one in the center toward the bottom, and two medium sized ones to the sides closer to the top. Slide the glass cover up and off. There are two more medium sized screws near the slots for the cover. Remove all five screws. The assembly with the glass comes right off, allowing you to clean both sides.