I wanted to leave for almost a year before I even considered discussing it with Mr Scully.
I'd take the children with me to the library and check out books on the topics of social psychology, mind control, brainwashing and propaganda, trying to deal with the cognitive dissonance of believing that I was not a victim of brainwashing / mind control (because that's what the WTS said), and the painful realization that my worst fears were true. I also started watching a Social Psychology course on the university channel and became fascinated with the inner workings of the manipulative nature of JWs.
The approach I finally decided to take with Mr Scully was similar to the one that was used in the Live Forever book - how it would be a huge betrayal of trust to find out that the JW leadership had lied to us. Then we looked up the definition of the word "lie" in the Insight volumes. The phrase "it is not necessary to disclose truthful information to people who are not entitled to it" blew him away once he realized that regular R&F JWs could be included in that group of "people who are not entitled" to honesty, especially once we started turning up one example after another of dishonesty within the Organization™, and dishonesty as a lifestyle choice of many of the JWs we knew.
It took about 6 months' worth of breadcrumbs, but eventually he said he was fed up with the dishonesty in the religion, and we started making an exit plan.