Dictionary.com
Thesaurus.com
Synonyms

turn over a new leaf

Cultural  
  1. To begin anew; to change one's ways: “Since he was grounded, Larry has turned over a new leaf and does his homework every night.”


turn over a new leaf Idioms  
  1. Make a fresh start, change one's conduct or attitude for the better, as in He promised the teacher he would turn over a new leaf and behave himself in class. This expression alludes to turning the page of a book to a new page. [Early 1500s]