My 3-year-old first-gen Apple Watch 42mm has started to drain its battery fast. I can't get through the day without recharging it, and its battery life seems to be getting shorter by the day. I've started to ask, and getting mixed opinions. Some (including shops) say it's a complete replacement of the Watch that's needed, some say I could replace the battery. Anyone have experience or insight into how I might go about replacing the battery of my Watch? Thanks!