Thanks, this was very helpful.

This is my first MOD install, so I have a bit of anxiety as I have a rather large product database (yes, I did backup).

I have made an over-ride directory (Magic). So, the code:
includes/languages/english/extra_definitions/YOUR_TEMPLATE
includes/languages/english/YOUR_TEMPLATE
includes/languages/english/html_includes/YOUR_TEMPLATE
includes/modules/sideboxes/YOUR_TEMPLATE
includes/templates/YOUR_TEMPLATE


I think I would change to :
includes/languages/english/classic/extra_definitions/magic
includes/languages/english/classic/magic
includes/languages/english/classic/html_includes/magic
includes/modules/sideboxes/classic/magic
includes/templates/classic/magic

??

Or do I need to be AT the same level as "classic"?