If they are to change, it will be because they wanted to do so and not because you want it; as simple as that. Just put yourself in their shoes and imagine if your partner wanted to change you.
What would you think about that? Probably that he doesn’t love you the way you are and that he wants you to be totally different. Now you know how guys feel when you try to change them.
So, whatever you do, don’t change his lifestyle and his habits because even if those things are imperfect, they make him so perfect for you.