there are plastic clips that hold the case together. after you unscrew the four screws at the bottom, be gentle and pry apart the case so that you don’t break the clips. The clips are the press to fit type. Size the stick on something like wax paper as you will want to reapply the sticker to the bottom after the camera is reassembled.
this is information on people swapping the lenses.
The lens assembly should be replaced as a single unit. In the article, some people swapped a single lens, but this will introduce stitching errors.
If I were were, I would wait until I found a unit with cracked lens and try to buy it for under USD $50. Alternately, you may be able to sell your unit with working lenses and get back some of your money. If you sell it, just tell people it does not boot and that it is only for parts.