i revised 2 weeks prior to the exam when i did this, and found the perfect method.
get a CGP book for it (make sure you get the right one), and just summarise the whole book. my notes covered the whole book and only took me like 10 pages or something. then do past papers and semi-memorise answers (a lot of the questions were repeated in papers from what i remember)
i got a high A, and would have probably gotten an A* if they gave me the opportunity to bash islam