"How do I make them want to...stop drinking, start studying, spend time with me, help me with the chores, be responsible with money, show up for work, take care of their health, talk to me about problems, help themselves or stop hurting themselves...?"
It's a common question pattern. The less-often-stated, but more revealing, question is, "How can I get them to do what I want them to do? If they would, I would feel better." Ouch.
People don't generally make lasting change to make someone else feel better. When or if they do, it often leads to other problems, co-dependent or enmeshed relationships.
People are most likely to change when they experience acceptance right where they are at.
"I can not condone what they're doing! I just don't agree. I can't just look the other way?" Acceptance can be offered without agreeing, understanding, or celebrating the behavior of another.
While acceptance isn't easy to offer, it is possible. This phrase has helped me, "If it were so easy for them to change, they already would have. While I might think that it's not that hard, I'm not them. They have all the information they need for whenever they choose to apply it."
I've found that if I focus on changing my behavior toward the other person, it often creates an atmosphere where they can more freely choose to change rather than feeling controlled.