There is but one way, and that is through following God and obeying God's law found in the Holy scriptures. "The fear of the Lord is the beginning of knowledge; Fools despise wisdom and instruction." -The Bible, Proverbs 1:7. This is the only, if we all have the right to choose the way we live, than how can we tell another they are doing wrong, when they are just choosing to live differently than you. We can not, so you see, there is only one way. And that way is God.
No outside force can change a person. Everyone has the right to run their lives as they choose incurring the consequences.
A person can only become 'good' by their own choice. If you want to find some way to influence their decision on whether to do this, it would probably depend upon the person.