Go and buy the book, simple as that.
Order off amazon. I’m a huge Harry Potter fan, and downloaded it ruins the experience of when you get the book in your hands and instantly are off too read it. I preordered mine, so it would come the morning it was released so I think the rest of you should go and buy it or order it rather than sitting with you eyes attached too a screen, when with a book you can carry it off and take anywere.