I saw this other guy asking how you'd download protected drive only view documents. So that reminded me of that other annoying characteristic of PDFs. They're 'protected'.
How do you deal with PDFs that are inherently uncustomisable and have fixed formatting? I appreciate the KO Reader and other readers can do reflowable text, but I'd prefer not to and epubs/txt/any customisable format would be better.
Yeah, PDFs frequently make each line, word or sometimes letter its own textbox to ensure consistency when rendering. Did you try the open source ebook manager Calibre for desktop or Librera Reader for Android?
Also, utilities like qpdf can remove a PDF password (provided you know it of course – though you can guess with quick, unlimited retries).
Calibre is the way to go. It’ll convert quite happily to epub, html, whatever. I just converted the Linux From Scratch book pdf in to epub and mobi for my kindle.
If you just need to edit a pdf and change some formatting on a line, try LibreOffice Draw!
If you have one of those really annoying PDFs where the structure is all crazy or some letters are pictures, etc., it is possible to OCR them with a mask on page numbers.
There are also tools which can just extract the text elements and smush them together, but as others have said, this doesn't always works as intended.