If you change him, he may resent you. Especially if he doesn't feel like he needed to change, nor actually internalize what the issue was from the get go. If you have to tell a man something and he doesn't want to change, forcing change on him is never a good thing. It actually speaks volumes as to the future of your relationship, and how willing he is to compromise and make you happy.
How long will it last?
If you have to push for someone to change, how long will it last before the person reverts back to his old self? Old habits die hard, a person that doesn't want to change because he sees the validity and need, is most likely just going to continue his behavior.
Acknowledgement of change and the reason for change are extremely vital in both the longevity and genuine nature of the change. A person who truly sees and understands that they want to change because it would make the relationship better, or better that person, will be more successful in changing their ways, versus a person who changes for the sake of their partner not yelling at them.