I would also recommend an exit strategy, especially since you have family that are Witnesses. I was lucky in that I had no Witness relatives--less lucky in that my wife was, and still is, one of them. But I had been grappling with my issues for a couple of years when I finally said, "No more." I left rather suddenly and the word "disfellowship" never even came up.
But not all congregations are the same. Many people here say they rarely heard from anyone when they "faded", but I sure did. I was on again, off again for some time, but my withdrawal was probably seen as somewhat abrupt. When I left, I would sometimes get 22 messages on my answering machine in a single day! Between that, and my issues with my father (non-Witness related) I finally tossed the answering machine out altogether, but kept my caller-ID. Remember, if they leave you a message, they'll expect to hear back from you.
After a couple of weeks, the calls stopped, but I kept having to deal with the self righteousness whenever I was out and about or whenever an Elder dropped by to "encourage" me. My wife was no help in avoiding this sort of crap because she wanted them to succeed in "reactivating me." I have no doubt she worked against me on more than one occasion, too. Eventually, they realized that I was finished with them and now they rarely bug me. I am still free to speak to my in-laws, though I don't always want to.
To be honest, I don't know why you couldn't just sort of stop going out of the the blue--except they would be more likley to love bomb you to death as they did with me. Maybe someone else has a different experience. But as long as you don't admit to doing anything they consider evil or start inciting a revolt among the rank and file, I'm not sure they have any real grounds to disfellowship you outright. They will bug you to death for a month or more, but some might prefer to take their medicine all at once instead of dragging it out over a year or more. You'll have to decide that on your own. Maybe others have different experiences that could help.
Just remember one thing: when they bust their butts to make you feel bad or guilty, they are doing it for themselves. Not for you. They will swear it is for your beneift, but they are fooling themselves. It's all about them and their need to force you to believe. So don't let them get to you. As you will soon learn, we're all full of suggestions and experiences. We might be able to help you if you get into a tight spot.
IsaacJ