Use Skittering. Textbooks take 25 to 75 hours of reading using the traditional method 1/3rd the time is 8 to 25 hours. Remember also get it faster in multiple passes, Hold the purpose and question in your mind while skittering or Superread And Dipping. It means you might go over the same page 3 or 4 times but it's still faster than traditional reading because you know what you want to know and can look over it faster.
Alex