For me rather quickly. In December 2007 my mind broke free, and I finally realized the lies. My wife arranged for a shepherding call so the elders could address my concerns. She thought that would do much good. The irony was they had literally ZERO answers besides "they're imperfect men" and "wait on Jehovah" and "it's the truth". That actually made an impact on my wife, but it took a few months. The brothers never really approached me again, besides an occasional "how's it going" after a Sunday meeting.
In the mean time I only attended Sunday meetings to keep the wife happy, but that lasted only a few months. My last meeting was the Sunday in early 2008 where they announced the cancellation of the book study.
By May 2008 my wife was out for good too.
As with reasons, my only goal was to not get DF'd. This was only for my mother and my mother-in-law. By not getting DF'd it would make associating with them much easier. I also wanted to exit slow enough to get my wife out too, which it did!