When I download Gutenberg books, I use Calibre to normalize the layout of each book, so they all have the same font size, paragraph layout, etc. If I ever purchase B&N content, I'd like to do the same.

As I understand it, I'd have to root my Nook to get access to the books, remove the digital restrictions management, convert with Calibre and then side-load the books. At this point, I would have two copies of the same book. I presume I'd have to remove the book (permanently!) from my B&N library if I wanted to only see my new, converted copy, otherwise, even if I removed the file from my Nook, it'd still see the "master" copy; is this correct?

Better question, perhaps: what is the best way to convert purchased content from B&N and put it back on my Nook?