If you've got a couple of quartz watches, do yourself a favour and pick up one of these cheap watch tool kits

They cost about 15 bucks, watch batteries are a couple bucks a pack, it's super easy to replace them, and to get it done by a jeweller costs 10 bucks

Change two watch batteries and it's paid for itself

Also includes all the stuff for sizing bracelets and changing straps, well worth it