You can buy watch tools on ebay. I have an adjustable watch back remover which enables me to change the batteries in all of our watches. Simple to do. Simple to search for and find replacement batteries. No more "While you wait for me."

Dan
December 2017

Take the back off
Remove the battery
Put the new battery in
But the back back on

Not rocket science...
February 2016

Why not do a Google search for - say - "replace fob watch battery video"

Huh?
February 2016