Explain how to break/change a habit?

is a psychology question , using classical and operant conditioning. if anyone knows please answer my question thanks.Explain how to break/change a habit?
Find a new one to replace the old one with.Explain how to break/change a habit?
if you had a determination to change you could.stay away from the people that could influence you..try to do the things you didn't do.
search a better thing to do / to beleive a better value than the one to break. it is pointless to break habit over nothing.
using classical conditioning you can break a habit by implementing negative reenforcement. But some psychologists think that positive reenforcement will change a habit faster than negative reenforcement.
IT TAKES 21 consecutive DAYS



of doing anything regulary/daily for it to become a 'habit,' is a generally accepted (scientific?) principle is what I've always heard.



it's said that it also takes 21 days to break a habit - replace it with another as said by another poster....