I got mine a couple of years ago in Alberta. In order to prepare for the test I took a course at NAIT through the mail, I didn't have to attend classes. After 5 months I took the exam, it's a 7 hour exam, the first part covered apprenticeship, WCB, unemployment and other regulations. The second part of the exam was code questions, a lot of calcualtions were on it. The exam was hard, but if you know the code you should do alright. Once you pass, you just have to renew the license every year for a small cost.
I received mine about four years ago in Alberta. You asked if it was hard, I guess the best way I could answer that is to say it was alot of work. I took a course offered at the college in Calgary (S.A.I.T.) prior to challenging the exam, the course was 84 hours in duration and the cost was just shy of 600 bucks...worth every penny! The course content was based on Canadian Electrical Code; Alberta STANDATA; Industry Training Act; Electrician and Apprentice regulations; O.H.S.A.; WCB; and Permit Regulations. I studied every chance I got and it paid off. Just as CRM said the exam was 7 hours long, 3 1/2 hours, a lunch break, and then another 3 1/2 hours. The way I remember it the bulk of the exam was calculations and code. I really enjoyed the course at SAIT, it covered an awful lot of material in a short time but it was a huge help in enabling me to pass the Master's exam. I would definitely check out your local college to see if they offer the same type of course. If you contact the authority that administers the exam in Ontario, I am sure they would be able to answer most of your questions. Good luck and enjoy the challenge!