A good example of leading......... not telling or insisting........ Zing.
The wall that the JW believer has built re their beliefs has to be brought down by that individual JW themselves. It must happen through their own research and their own process of establishing real facts and real truth.
The problem is Cognitive Dissonance. This is the main reason every conversation breaks down into an argument, hostility, or gross indifference to what you as a non believer has to say.
Cognitive dissonance is a concept in social psychology. It is the discomfort felt by a person who holds conflicting ideas, beliefs or values at the same time. In this state, people may feel surprise, dread, guilt, anger, or embarrassment.
In short: In the field of psychology, cognitive dissonance is the mental discomfort experienced by a person who holds two or more contradictory beliefs, ideas, or values. This discomfort is triggered by a situation in which a person's belief clashes with new evidence perceived by the person.
This is the working theory why every conversation with a believing JW usually falls on deaf ears. It becomes so disruptive that even the closest family member will be rejecting all the common sense you offered (been there tried to do that) because your 'truth' can not be fit into their 'truth'.
Eric Hopper wrote in The True Believer:
"All active mass movements strive, therefore, to interpose a fact-proof screen between the faithful and the realities of the world. ...by claiming that the ultimate and absolute truth is already embodied in their doctrine and that there is no truth nor certitude outside it. ...To rely on the evidence of senses and of reason is heresy and treason. It is startling to realize how much unbelief is necessary to make belief possible. What we know as blind faith is sustained by innumerable unbelief's."
Zing gets the right way to help people out of the religion.......... people have to be encouraged to look into their religion for themselves.
If you don't get that need from a JW to question their religion there is not much you can accomplish.