Migrating from Calibre Portable to Calibre for Mac

I originally started using Calibre for Mac four or five years ago. For quite some time, though, I have been using Calibre Portable (which is only compatible with Windows). When I moved from Calibre for Mac to Calibre Portable, I essentially abandoned the library I had on my Mac and created a new library in Calibre Portable.

Now I want to move back to Calibre for Mac, but I would like to essentially override my old library and preferences with everything from Calibre Portable—basically a clone of my Calibre Portable library on my Mac. How do I replace my old library and Calibre settings with this new/updated library?

Thanks,
mdclanahan