Studying full time, you should be able to pull it off. I started FAR essentially the beginning of March and took it 4/19 and scored an 85. I'm using CPA Excel though. I went through each section writing notes and making sure I understood the material before moving to the next section. I only answered 1 question from each section just to mark that I had gone through that section already (unless I had difficulty understanding then I'd do a few more MCQs). After getting through all sections, I had about 2 weeks for review. I made sure I completed all ~1400 WTB questions in that time. Last 2 days I did take off work. I reviewed notes and did a full practice exam.
I know this was more than 4 weeks, but I did this working 40-45 hours per week, 2 classes (Practices in Accounting and Auditing and Attestation), 2 kids (both in sports, 1 in travel soccer and I didn't miss a game), and a pregnant wife. Not to say you have it easier not having to work or anything, because studying for FAR is brutal no matter what, but just to give you perspective on what's possible.
Main thing for me was discipline. Strapped myself to my desk every night for 3 hours (when I didn't have class Tuesday and Thursdsay night 6-9p.m) and put in about 10 hours each weekend day (when there wasn't an away game). Right now at my desk studying for AUD instead of celebrating my FAR victory (although the whiskey will flow in a couple of hours).
Good luck, you can do this!
FAR: 4/19/2014 - 85!
AUD: 5/27/2014 - 90!
REG: 7/18/2014 - 81!
BEC: 8/13/2014 - 84!
4 up, 4 down, in 4 months.
Licensed 9/22 in NC.