Trouble with air law is that there's nothing to understand, you just have to memorise it. That's not how I learn - I remember how things work, then if stuck in the exam I can work out the answer from first principles. This doesn't work with air law.
If you're useless at memorising unconnected meaningless facts, like I am, then it's going to be tough ... but the good news is that the other exams are nothing like as bad in this respect.
For your own purposes, as opposed to simply passing the exam, you need to work out which bits of air law
(1) you need to know to stay alive
(2) you need to know to avoid seriously expensive prosecution
(3) are irrelevant twaddle that you can forget the day after the exam.