The answer for this FAQ should be much simpler after we finish this task:
https://github.com/ClassicPress/ClassicPress-Migration-Plugin/issues/27
For now, @Dick_Metcalf what you ended up doing (ask your host to restore a backup) was the easiest solution if it works, but not all hosts will have this.
See also: Can I convert a WP site to CP – and what if I don't like it?