Look at the high yield topics, try to teach it to yourself. Don't get too bogged down on the finer details, it's really the broader concepts which will allow you to apply your knowledge. Trust that you know at least some parts.
tbh I feel like it'll be fine. Just make sure to plan out your marks so you hit the points exactly. They can't mark you down for putting the right stuff in.
also writing paragraphs would be better in some situations if you have 0 clue what you're talking about