Fixing a Bushnell scope (1 Viewer)

Hello, I am new to this forum and am looking for info on how to fix my Bushnell spotting scope which is at least 20 years old. It is a 15-45XD60 mm, in a series 78-5456. The whole unit has become slightly separated at near mid length, feeling like there are one or more loose screws holding the two main parts together. I cannot figure out how to tighten up again. Any help will be much (!!) appreciated.
Art

p.s. I have experience fixing microscopes but this one is a real puzzler.