Yes, three separate elements. Once you get the front cover off and the lens removed (check infinity focus first), the front part unscrews. Check around the side to see if there is a set screw for it. As OAPOli says, keep notes and photos on orientation of the spacers. And the middle element. When it first comes out, feel the surface on both sides; you can feel that one side is curved more but it is hard to see. I'll put an arrow on the side of element in pencil, also.
Soak all the glass in ammonia and hydrogen peroxide for a night. Then see what you have. The nice thing is that the viewing lens does not have to be in very good condition to work perfectly well.
Replacement lenses are out there. Drop me a message if you want to talk about one.