If you want to uninstall OS X
Just boot into OS 9. Trash the following folders:
System
Library
Applications (unless you have some carbon apps in there that you have been using)
All those lil' UNIX folders (usr, etc, var, tmp, ...)
Anything with "Mach" in it
In your OS 9 System Folder, take out everything with "Classic" in the name (Classic Support UI, etc...)
And keep the user folder.
*gasp* how anyone could do such a thing, I do not know