there’s no right answer to these kinds of questions. This is like asking that how much practice will it take for me to run a sub 3:30 marathon. It all depends on your current situation, what your background is, how well your preparation has gone so far.
This is how I see it: this is the last hurrah. Review until you know this stuff like the back of your hand. How many hours it takes doesn’t matter because if you fail, you need to wait another year, which is a much greater pain in the ass than putting in the extra hours of review now.