I like the old Citizen titanium Promaster models. But the ones I like are ~15 years old, which means the capacitor/battery is usually finished. Citizen here either won't touch them at all or charge about the same as buying a new one to service them. I can buy the batteries but just can't open the case.

This is the sort of watch:



Does anyone know what tool is required to DIY (and, err, how to do it)?