-I have an extensive list of their false prophecies
When you give him that list....tie in the scripture at Deuteronomy 18:20-22
When the prophet speaks in the name of Jehovah and the word does not occur or come true, that is the word that Jehovah did not speak. With presumptuousness the prophet spoke it. You must not get Frightened at him.
If there is some way that you can get him to read Raymond Franz' book COC he should surely come to understand that the Watchtower is not the true religion.