It sounds like you will want to mind map and do syntopic reading.
If I were in your boots I would make an effort to PhotoRead as many of the PDFs as I can in a 30 minute period, daily for a week or two. Right now and then for two to 3 weeks prior to the exam as part of my review.
Mind mapping is important. So you have something to refresh your mind in the last 4 weeks before the exam. Because human nature is that you will forget almost everything you learned in the first couple of months if you don't have reason to start using the information. Having something to review and look at saves a lot of time re-studying.
The review procedure is review once at the end of your study period (before a break) and review immediately after you return to a study period or a break. Review daily for a week and once a week after that. It helps keep the memory sharper about the information.
Remember use it or lose it? Well reviewing is using it and it only takes 1 to 3 minutes to review a mind map.
Do any quizzes or questions. They actually help you get clear on what you should be looking at in the subject. Get a hold of od exam papers with the same purpose in mind.
Do it early not merely days before the exam.
If you get stuck on understand and photoReading the section again hasn't helped... talk to someone about it. Even if they don't know anything about the subject talking loosens the minds blocks. Find someone you can coach you on the subject if necessary.
Good luck