Tell him to approach it on an emotional level. Remember, they truly believe he is commiting certain suicide by leaving the organisation, as Jehovah will soon destroy all who appose him. (apposing Jehovah and apposing the Watchtower Society seen as the SAME THING!) They love him and are practicing tough love. It isn't easy for them to shun him.
He needs to ask them how he is supposed to cope with finding out the Society is not God's organisation, humbly explaining the whys and how.