go through destroyer, make notes on what you didn't understand and read said areas in cliff's ap bio/barron's ap bio.
take dat bootcamp exams and datquestionoftheday to fill in kinks.
bio is just a race against time to gain exposure to as many things as you can. try to get a good grasp of major ideas (like respiration and photosynthesis etc because they focus on details as opposed to knowing some random disease that you probably never heard about). your best bet is to either read through a lot of textbooks and get familiar with some things you have never heard about (at least SOME kind of exposure) or do A LOT of practice problems.
i have my DAT next week, and i still am not sure if i'm ready for bio. just have to have a good enough foundation to at least make educated guesses for the random questions i suppose.