For this instructable, I inspired myself of all those watches battery changing tutorials videos because they all have a tool in comon : The screwdriver for watches. I thought that it was useless to buy that tool.
All you need is :
-a watch with a back you can unscrew ( like in the picture )
-a pair of scissors
-a wire (a pin)
-not a new battery, you don't know the battery number yet, (they are not all the same)
Step 1: Open the Bracelet
At the end of the attachment of the bracelet, there are some little holes,
you need to push on the telescopic pin that assembles the 2 parts.
Take your wire and insert it.
Step 2: Unscrew the Back
Put your scissors ilke in the picture below. Push hard on it and turn counter clock wise.
Step 3: Take Off the Battery
Take your wire and slide it gently under the battery. Pop it out.
Take a look at the battery and take in note the serial number. Go buy it, put the battery with the positive side up and put everything back.
There you go.