A change could be very easy. Open the door from the jail and let the slaves go.
If they drop the disfellowshiping and shunning, it will went down very fast. Then it's easier to make a change, because everybody can say and do how he like. If there is no risk to wake up people, the revolution comes from inside. There enough people waiting for the right moment. At this time it's a hard job, to wake up some friends.
But first the shunning had to stop. It's the only thing which keep the people in the cult. I think this will only ends, if there a lot of pressure from the outside.