From Longman Business Dictionary
relaunchre·launch /ˈriːlɔːntʃ-lɒːntʃ/ noun [countableC]MARKETING a new effort to sell a product that is already available, often involving a change in advertising, packaging etcIf the relaunch goes smoothly, sales should increase by at least 5%.
—relaunch /riːˈlɔːntʃ-ˈlɒːnt/ verb [transitiveT]The company aims to relaunch both brands.