Reverse compatability with basic DnD?


How much of the campaign book can be reverse engineered? Meaning about what percentage of it can be disassembled and dropped into a homebrew dnd game?
Classes (except Scholar), weapons, and creatures can be used in a regular game with a minimum of change. Magic items would be a bit harder (some of them involve powerpoints).

the background material could be used with as much ease as any other source material as the book contains most of the material from the Conan stories (names of places, types of people, ect...)