How can bad habits within society be overcome?

The reform of societies and the overcoming of their bad customs are achieved by adhering to what Allah has commanded and what His Messenger (peace be upon him) has guided to. This is in accordance with the Almighty's saying: "And let there be [arising] from you a nation inviting to [all that is] good, enjoining what is right and forbidding what is wrong, and those will be the successful," and with the saying of the Prophet (peace be upon him): "Whoever among you sees an evil, let him change it with his hand; if he cannot, then with his tongue; if he cannot, then with his heart—and that is the weakest of faith."