Updating a theme

I commonly duplicate themes to customize them for specific clients’ sites. Once I have duplicated a theme, and there is an update to the theme, how can I copy my edits of the original theme to the latest version of a theme?

Also, how do I tell what version of a theme I am using, from within my RW project? I have gone into the Themes folder to do a Get Info, but is there an easier way?

The AddOn Browser shows the version number in RW6.

Any edits you make to a duplicated Theme’s styles are stored with the Project settings.

Yes, but how do you update a customized theme to new version of the theme?