I was going to answer your question yesterday, but I waited until today because I'm only a 1L. I have received excellent advice, however, and thought I'd give you some direction.
My tests are all open book, but those who did well say they never had to access their outlines. I say outlines because you should not be dealing with notes after you condense them into an outline, and you must make an outline. Organising your notes into an outline, and memorizing the outline will get you much further than notes in a book. Why? First of all, an outline helps you synthesize the rules from your cases. Second, you will not have time to flip through pages in a 1000-page casebook and then sift through your notes.
I suggest you make an outline. Then condense this outline into a checklist (basically just topics).
Look through previous threads for advice--it's all here. You should approach a closed-book exam the same way you'd approach an open-book exam, with minor variations at the end of the semester.