Chunk it like work with it section by section or chapter by chapter... don't take longer for previewing than 4 minutes... (if previewing takes longer than 4 minutes it means you are probably trying to do too much at once).
Photoread the whole book and leave it... it will take longer than the tape... thats OK but work with it chapter by chapter... (PR only 3 to 5 chapters again that you are actually working with the book, for learning). Look at large text books as being multiple books bound together.
By sticking to 3 to 4 minutes previewing you are actually training your mind to get to the important stuff quickly. Initally it feels uncomfortable and with practice it becomes easier and much more productive.
Good Luck
Alex
