Only done Mod 1 so far and that took about 4 months with Bristol. My advice would be to not get too bogged down with it. Do enough to get 85(ish)% in the progress tests. The brush up course will hammer the rest into you properly. Momentum is the key! Non of it is difficult, just lots of facts, figures, tables and equations to learn.
During the brush-up course, try and do all the homework set for you - this will mean working every night to 12-1am but I assure you that will need to! You will be remarkably slick after the brush-up so long as you do ALL the homework!!
Contrary to FIS's advice, get the exams in the week following. I would not leave a gap as you need to keep on top of things for the three week brush-up and exam period. Just chill afterwards
