He sounds a lot like i was. I was "not the type" to do groups (GOD no!!). I was NEVER the type to go to a therapist. I did allow myself to read Mike Lew's book "Victims no Longer." It was a life saver for me.
From there, I was able to go to a therapist and eventually formed a support group.
Not anyone's recovery process is the same as another's; just as no two abuse scenarios are the same. Our brains and circumstances are all different. He really needs to know that. HE has to be the orchestra-tor of his own recovery experience.
YOU can be there best for him be remaining flexible, giving him space and letting him direct. But if he asks you for guidance, he means it.
But, as others have said ahead of me, you can get yourself a heck of an education on the topic and just keep it all to yourself until needed.