Start with a beginner's mind, and be ready to let go of trying to get some control over X that you would like to have. The more YOU let go, the better he will be toward the children. Sounds odd, but you need to give him space to be the generous, compassionate, empathetic, understanding father that you would like him to be. When he feels he has to play constant defense against you, he is busy trying to prove himself "right." Give him the chance to be a good dad, and he'll very likely start trying to improve things himself. (Basic principle: less old emotional overhead/defensive crap = much more energy to be a better dad)
