We do not suggest attempting to change the Watch battery yourself. We are required to advise that by utilizing another jeweler to change the Watch battery for your Na Hoku Watch, it will nullify Na Hoku's warranty against defects in materials or workmanship. The warranty will not be voided when having your Watch battery replaced at Na Hoku's Jewelry Manufacturing Facility or with a Na Hoku trusted local jeweler.You are welcome to take your Watch to a Na Hoku Store Location near you. The store location will then send your Watch to our Corporate Office on your behalf. Alternatively, you may send your Watch to us directly.