I am working full time as a consultant.
Sure, it is not easy but it is doable. Just like cgrady40 said, don’t plan on having too much of a life.
The very instant I got my results from Level I exams, I registered for Level II and started, so I almost had one year of preparation. The tough part certainly was screezing in some 2 or 2.5 hours in the afternoon/night right after coming back to the hotel from a day at the client. But you can get used to it: My colleagues were watching crap on TV to relax, I did some pages in CFAI texts. On the weekends, I tried to prepare and read for roughly 10 hours.
Elan were of a great help (yeah, that’s sarcasm!), as they shipped their Notes only after I had almost finished working my way through CFAI books. So I crossed them off my list without having looked at them much.
Then 2014 my company ran into trouble and I decided to look for a new job. That’s when my schedule went off plan. But in the end, I got a job offer, quit my job and “had” to clear my desk immediately with one month to the next job. Just guess what I did that month.
I had negotiated a two weeks leave prior to the exam at the new company. These two weeks were like crazy, 7:30 am to 11 pm (less roughly two hours for breaks) doing Mocks, tests and repeating the questions from the books.
In the end, I did them all: CFAI texts and questions, Elans practice tests (the ones that were available), Elan Mocks, Schweser Mocks, CFAI mocks.
Even if I had not quit my job and gained one month filled with CFA I had reached the 600 hours.
The “trick” is to start early and work steadily. Oh, and tell your family and friends that you will be away on some distant island for a year.