Take things slowly and do not attempt to rush the process. Be a friend, listen, allow him to come to you and talk. Do not offer up advice unless he asks for it. It took a long time for the crisis to occur and it will take some time for him to feel comfortable, not only in his own skin, but with all. He has a lot of guilt, and is afraid of judgment and criticism.
Here's a thread that I created many years ago that may provide some insight into reconnection for you. The thread is entitled "TMAK - Explanation of Reconnection.
The reconnection is the hardest part of the journey. Why? Because, if he is reconnecting, you will want to get things back on track as soon as possible and it will not work that way. If you push or things happen too soon, he could be right out the door once again. Patience is the key. Wishing you the best of luck and if you get frustrated, please come here to talk. The door is always open.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.