Running
without a restart.

Modify Keyboard Template under MacOS X by Michael Coyle

Are you itching to modify the keyboard maps under MacOS X? John Steed told me of an article at Macintouch that can get you started. The article lists a different location for the Localized resource file than where I found mine, but maybe the author is running 10.0.4. Once you have converted the Localized.rsrc file with QuickConvert, you can read this previous ResEx edit to start modifying your keyboard layout.