My watch stopped. It needed a battery. I was on a expedition in South America. How inconvenient..
Step 1: Take the Strap Off and Take a Breath.
Step 2: Flip the Watch Over
I used a knife to start unscrewing the back but I guess you could use a watch-back spanner
Step 3: Remove the Plastic Thingie
Yep you'll put it back in a sec
Step 4: Once You Remove the Plastic Thing
You'll see a battery. Make sure you replace it with the right one. I also used compressed air to clean out the mech while I was in there.
Step 5: Put the Back Back On