Have you got the PPL Confuser by Nung Sornying? Basically if you can answer all the questions in the confuser, you can breeze through the exams...
I'd say study hard for 3/4 days on each subject, should be enough time to cover most of the material. Then when you're done, attempt the confuser questions, and re-revise whatever you get wrong. Rinse and repeat until you are getting high scores in the confuser and you'll have no problems with the exams.