Any special gear for the battery change? Ground mat? Plastic tweezers?
No, nothing special. I open up the bracelet at the clasp for easier access. From an ESD perspective, I just make sure I touch the case so it's at whatever potential I'm at, which you can't help but do anyway. I suppose I don't blatantly take off my sweater on a dry day right before! The right size flathead for the caseback screws. If the caseback were stuck on it might be a bit scary to pop it loose, but mine's easy. The same screwdriver fits the battery retention clip. With that loose, but not completely off, I just push the old batt out with the screwdriver tip, and slide in the new one with my fingers and screwdriver tip. You instantly know it's working from the ticking...YaY! No WR warranty of course, but no one will give you that on a 45 year old!
Super impressed by your watch! have wasted (invested) the last few hours investigating them and where I can get one, its going to go on my "snatch one if I can" list 馃槣