My only advice is study, study, study! The NCAA test is known to be a bear. I know several umpires that took the test 2, 3, even 4 times before passing.
Just reading and re-reading the book is not enough IMO. You need to actually study. A link to past tests is
http://www.umpire.org/ncaa/ .
Pay particular attention to POE and changes.
When taking the test, remember that leaving out 1 possible selection, as well as having 1 too many selections, will result in a wrong answer on the whole question.
Study hard, good luck.