How Can A Sales Manager Thrive When The CEO Used To Run Sales?

The Situation
Jack, ABC Company CEO, was the main salesperson in the early days of the company. Over the years, he hired a few salespeople and built a team that reported to him. A few months ago, he hired Henry to be the full-time sales manager for the company. At least, “sales manager” is the title Henry was given.
Jack can’t seem to hand over the reins and let Henry do the job he was hired to do. Jack gets involved in deal strategy without Henry requesting his help. Because of Jack’s relationships with the salespeople, they go around Henry whenever they disagree with his decisions and Jack provides a receptive ear to their complaints.
Henry is beyond frustrated. When he interviewed for the position, Jack assured him that he would stay out of his way and let him do his job. So far, that hasn’t happened.
Your Challenge
When a CEO used to manage the company’s sales team, how can a newly-hired sales manager take the reins from him? What should the sales manager do to succeed in this environment?