I would encourage CEOs to observe their teams and look for bright spots as they happen. Then use these bright spots to gain momentum. Change is easier to take place once you have some momentum. Momentum allows you to counter the natural tendency to stay the course and not change. Change is difficult and a process. Anything you can do to gain some advantage is helpful. Be careful not to sabotage your own progress by being critical of small improvements. These small improvements, with momentum, can become snowballs of change!
How about the board of directors? My encouragement to the board is to be encouraging and patient. Rome was not built in a day. Said another way, it takes a lot of mangoes to teach a monkey how to skateboard. This story was shared in Switch. Basically, it means that it takes a lot of encouragement and positive reinforcement along the way to learn new and difficult skills. So hold off on critical remarks, and be encouraging. Throw your CEO a few more mangoes especially when bright spots emerge.
And never, never end any meeting with a criticism. Try a mango instead.