Pay attention. This is important.
I'm not someone who's great with change. Actually, I suck at it. But even though I don't like when things change, I'm wise enough to know that I can't change other people. The only person's change that I should concern myself with is my own.
My boyfriend used to smoke almost a pack a day. I've never been a smoker and can't stand the smell of smoke. I was worried for his health, but I knew if I bugged him about it he'd think I was nagging him. And despite the benefits that stopping smoking would bring him, he'd get more determined to continue smoking the more I tried to convince to quit. So I did nothing.
In time, he realized how smoking was harming him and he quit on his own. He's now such an anti-smoker that he can't even stand to go places where smoking is permitted. The point is, he had to make that change for himself, not for me.
1. They must want to change on their own.
People only change if they themselves want to change. You can manipulate, cajole, implore, plead, and bargain with them, but ultimately they're not going to change unless they want to. They may say they'll change to appease you, but no matter what you do, if they don't make it happen, it won't.
It also doesn't matter how frustrated or angry you get; if they don't have that inner fire to change, nothing about their behavior will be altered in any way. If your significant other has low self-esteem and you want them to be more self-confident for themselves, although your intentions are good, it won't motivate them to do what they have to do.
If someone does change their habits just because you want them to, that change is going to slowly dissipate until they're back to having their same habits that you wanted them to get rid of. If you can't accept who they are, move on.
So now that you know that, how can you help this person?
Concern yourself with yourself only.
It's not your responsibility to change someone else. Concern yourself with you. If you don't like how they are now, you're not going to like how they are once you've fully established your relationship. If they ask for your help then you can step in, but if they don't then keep your opinions to yourself.
Whatever you do, don't go into a relationship with the idea that a person will change once under your influence. Besides, when you think that way, you're not showing them unconditional love — you're kind of being a jerk.
And if you're so into change, change yourself. Luckily, none of us are perfect so you'll have plenty of things to modify, adjust and reboot about yourself. If you continue to have the urge to get someone else, could you be avoiding something about yourself that you don't want to deal with?
Change is difficult and it's much easier to get someone else to do it than ourselves, but it's crucial for our growth as humans.
Change can be scary, but it's a good thing when the only person we're changing for is ourselves, not because we feel forced to do so for another person.