You have often heard the expression "a leopard can’t change its spots" when talking about someone else’s behavior.
We know it is impossible for anyone to change someone else, but it is ok to point out to someone how their behavior impacts you and them and how they could consider modifying it. Now, we may be told to get lost or we may plant a seed of thought in that person’s head that leads to some sort of change in their behavior.
The first step in any personal change is becoming aware of and accepting what it is you want to change. It is then seeking the help and support you need to make that change. That may be friends, family, a therapist, self-help books, clergy. You may feel strong enough to make the change unaided, if so, good for you. We are not leopards so we can change our "spots"; we can become whatever we want to be, it is our choice.