Thanks for the answer. The book consisted of images only (quite a bad scan, actually) so the first method would actually work well. What would you use to extract the PDF?
At the end, I decided to use Foxit PDF Editor which is my favorite program for PDF edition. When it comes to rotating pages, it is quite unhandy though - I needed to click four times for every page and it took me much longer than 10 minutes

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I'm still looking for a better solution for future use.
Adobe Acrobat is too expensive.