Along with the articles on killing apostates, it's good to show Duet 18:20-23, about the prophet who presumes to speak in Gods name and the test if the prophet is true or not. It says if not true he is to be put to death.
Then show what the first page of the awake magazine said for many years to the effect of, "The creators promise that those who saw the events of 1914 would not perish until armageddon comes" or something like that. And some articles about the GB being modern day prophets. So the GB put WORDS in God's mouth and promises he didn't make. Ask the person did Jehovah lie, did he make a promise those born 1914 wouldn't die until the end? Or were those man's words?
So since according to the OT the GB are false prophets, they are to be executed, but due to the laws of the land and the laws of Jesus they can't be executed, so they are to be disfellowshipped for false prophecy, shunned, and await death at armageddon.