Multiple superreads and dip. In day four you'll be looking to answer more questions and each question warrents a superread and dip. This means you might be pausing to look at the next question. Going back in part of the book where necessary and in one way or another you'll go through the whole book.
Day 3 you aim to get through the whole book in one superread and dip. It's factored in that you probably won't have many clear cut mind probing questions and you purpose might be changed after this superread and dip.
For day 4 don't worry too much about "going through the whole book" from beginning to end. You'll jump around more. Just be sure you don't only passively read a couple of pages in one chapter during that 30 minutes. Open the book and go to where the information is and dip then move on to superreading again.
Alex