Greetings student1,
I'd say that, as long as he is willing to stay in contact with you, you should do your best to help him see the light. I think you need to probe the internal self-evident Watch Tower dogma which is actually weakest, the preaching work. World wide the JW ministry is a dismal failure and comes no where near the mandate set out in the scriptures that the JWs use to justify the nearness of Armageddon. The preaching work could NOT possibly be nearing completion since vast areas in the Islamic world, and most of Asia remains untouched by the "life saving" message of the Watch Tower Society. Anyone with 1/2 a brain can do the math and realize without any Apostate information that it would be a gross miscarriage of justice for ol'Jeehobie to kill billions of people who have never even met a JW let alone heard the message.
The "collective guilt" theory used by the WT Society to justify the death of these uninformed billions is without any biblical basis. It also would prove God to be a rascist with cultural prejudices bent on genocide if the Watch Tower position were true. If there is any logic left in your friends brain the simple facts about how little the Watch Tower has done to get their message to these neglected areas should at least start him thinking about the glaring contradictions within this Watch Tower dogma which may, in turn, allow him to see the other problems with the entire belief system.
The other huge logic problem the JWs have is that their over all numbers cannot keep up with the population growth. In short, the longer Jehovah postpones Armageddon the more people will actually die since it is NOT possible for just seven million JWs even preaching nonstop for 24 hours a day seven days a week to contact every single person on earth even once, let alone to start bible studies with them, before a whole new larger generation of potential converts would be born. No Apostate info needed since this is a simple math problem. Numbers don't lie.
Math alone proves the Watch Tower Armageddon just would not be possible since billions now have never heard the message and every year God waits millions more are born who would all need to be contacted. How anyone could think that the Watch Tower's Jehovah was merciful or just in starting Armageddon after running the numbers is just beyond all reason. This immense failure of the Watch Tower to reach every corner of the earth with their salvation message was one of the main lines of evidence which allowed me to see that the JW belief system was deeply flawed.