What words indicate that a person has decided to change his behavior?

repent, have a change of heart, reverse your behavior, reform, go straight

What words refer to an admission of wrong?

admit wrong, confess, acknowledge wrong, take something back (that you said),

What words refer to an effort to make up for doing wrong?

make amends, make up for, set things right, make restitution, pay back what was taken, return stolen goods