I took in LA back in September, spent a couple of days looking through first aid and the green NMS book.
The scenarios are all very basic and in hindsight my preparation was a touch of overkill.....
I would say brush on stuff that perhaps isn't second nature - CNS, psych, obs... and take time to practice scenarios and history and exams in real time - I think that's the best for repeativeness and focused preparation and will avoid any nerves on the day....