USE INSTEAD›to start using another thing or person instead of the one that you are using now: We're thinking of replacing our old TV with a fancy new one.
BE USED INSTEAD›to start to be used instead of the thing or person that is being used now: This system will replace the old one.
GET SOMETHING NEW›to get something new because the one you had before has been lost or damaged: We'll have to replace this carpet soon.
PUT BACKformal›to put something back in the place where it usually is: She picked up the books and carefully replaced them on the shelf.