Quote:
Originally Posted by theducks
Sounds like you want to use a Bulldozer when a Garden Trowel might work 
Install the Quality check PI if not already done 
Run Check ePub Structure: Check DRM
Export to a JUST THOSE ePub files to a folder
Now DELETE FORMAT EPUB on those
Assumes those tools have been installed
Then Add books those you saved
This way, all metadata stays intact and you did minimal work on your library |
Much simpler: "Open Containing folder", drag file with DRM to the book details pane in Calibre for that book. (Been a while since I used that, but in the past it worked)