I have some ebooks which are converted from other formats to ePub. Some are ill-formatted: there are hard line breaks in words and orphaned page numbers between paragraphs.
How can I repair these ebooks? Do I have to open and edit the source files, or is there a better way?
I use Calibre on Windows to organize the ebooks, if that matters, but I am not bound to that program, and I can use Linux too.