Non-fiction??? How can you change anything anyway?
Well, as an example, I have an early nineteenth century copy of Culpepper's Herbal. The language and terminology is so old-fashioned that many a modern reader would be confused by it. The edition is out of copyright, so I could rewrite it in modern English, lift some of the wonderful drawings, republish it as something like 'Culpepper's 21st Century Herbal' or some such and put my own name to it. Not that I'd want to and I think it's already been done anyway, but legal matters apart, it's feasible.