If I were his agent I would, of course, have him vow to remain sober. The thing is, that is not his real transgression, and he has never spoken to his real transgression, at least not eloquently and directly. I would have him apologize to his owner and fans and team mates. I would have him say that he now gets that he let them down, not just himself. I would have him say that he understands that not being reliable, all because he wanted to get high, meant he was not there for them when they were planning that he would be. I would have him apologize to the league and to Goodell personally saying that the league is not there for him, but that he would like to be there for the league. I would have him say that he understands league policies are intended to allow it to grow in its contracts and endorsements and that petty foolishness by him have been a distraction to that goal. I would have him say that in some small way he has made marketing the game incrementally more difficult hurting the league and the players in contract monies. I would acknowledge that the league has spent far to much time and energy on the case of someone who tried to throw all his gifts away, and that if the league saw fit to reinstate me that it would never happen again. He needs to make the league think that he gets it and would be a good business partner, even a poster child for understanding that the players and owners are interdependent.
Frankly I think he has very little chance otherwise. His only value to the league is if he produces it by supporting the league rather than himself.