If you want to pop through the wiring diagrams at the12volt.com you might be able to figure some out, not sure in bypassing the amp or if it will just amp twice or how that would work. I know a few people have done the swap...
If this is a "got a dual media cheap/laying around" thing, I would really just get the stock replacement or the single CD unit that plugs in with your existing harnesses if you want to go stock (plus the green '98+ radio lights won't match your ice blue '97 lights) unless you have a massive box of cassettes that you really want to listen to.