If you're gonna eat a whale, you gotta do it one bite at a time.
It would help if you are curious about the subject matter. Curiosity is an amazing motivator for reading.
What secrets does the book contain? What is it going to teach you about the universe? What parts of this book do you already understand?
What's the chance there's something in that book that will help you reframe something else in your life with new information?
What information in the book is going to be on the test?
If you want to know the answers to those questions, or the other questions that you might have floating around in your head, the only way to get them is to read the book.
Don't read it because you're being forced to read it. Read it because you want to know more. You want to be the kind of person who knows things. And the only way to actually know things, to have crystalline knowledge, is to read the books that contain the information that the people that have come before you have sorted out and assembled for you to absorb.
Surely you have a goal in life. You wouldn't be forcing yourself to study in college if you weren't trying to reach a goal. Reading these books are parts of the path that you're taking to reach your goal.
If you can internalize this concept and apply it to those books, reading those books is not going to be a chore. It will become fun. It will become exciting. You will read faster and flip through pages faster and train yourself on how to absorb information quickly.
People achieve what they believe they are supposed to achieve. They go in the direction that seems most right to them.
Seems like reading these books are the right direction for you, and once you make it through, your mental muscle will be much more defined and impressive for the effort.