Don't hold out any hopes of a normal family relationship in the future though. It'll only get you more and more frustrated. Don't tell them anything about your new life whether it be good or bad. Because they'll latch onto the bad and say "see what happens when one leaves Jehovah's organization".
I know that a normal relationship with my family is virtually impossible at this point, and even just getting one member of my family to communicate with me is unlikely, but knowing that I've left a path for them will make me feel better about the whole thing regardless.
#2 Go out with a bang, big time letter, a lot of good arguments that will not, in general, move a single JW.
Why? Because this is a club and it's due's paying membership and their good standing counts for more then a non believer's truth.
#3. Move out...... say goodbye to your close family relationships and count yourself lucky because you will no longer be in their pathetic lives or under their influence. I know....... it's Mom and Dad....Sis & Bro...it's been your life....unfortunately if you don't think as they do....... they think less of you.
I've been thinking about what I'll put in the letters, and I've decided that I'm not going to present the specifics of my argument there because I don't think it would serve a purpose. Instead, I will offer to explain my reasons to them should they wish to resume contact with me, however, I will also tell them that they don't have to listen to my explanations to get back in contact with and I would be more than happy to simply leave it as something we disagree on because I don't have to force everyone around me to believe what I believe.