Well, it depends on various factors like are you working or a student. If you are working like me it can get quite tough like I have preparing since April but I haven't been able to prepare consistently the way I would like it to be. On some days I would give 2 hours of time for the preparation, and on some days no time at all. So it can get difficult if you are into job unless you are able to maintain a schedule of at least 2 hours a day. And if you are a student then I think a couple of months should be sufficient to make yourself ready for the exam, given you are studying very consistently !
When people don’t understand what you are doing they call you crazy. But this tiny ad just doesn't care: