I say **** it and cram, get a **** ton of red bull/coffee, it will keep you awake through the night and the exam, tiredness will kick in later that day but as long as you have a good nights sleep and not an exam the next day it docent matter. Literally just read through the notes/textbook 100x over and do past papers, yeah its boring af and you will probably get to a point where you will think 'might as well just sleep now' but to put it in perspective its one boring/tiring night for a grade that will stick with you for life, if you get like a D or E you will regret not staying up this single night to do a bit of work that could bring you up multiple grade boundries