Although Fossil wristwatches are fashionable, durable and solid, they do lose battery power over a period of time. The unique pressurized assembly of a Fossil wristwatch keeps out water and dust but also makes them difficult to open and change the batteries.
Spread a clean cloth on your work surface and place the watch face-down to avoid scratching the face of the watch.
Locate the four slots on the back of the watch and insert the screwdriver into one of the slots. Apply pressure to the screwdriver and move the back plate counterclockwise until it can be removed.
Pry up the edge of the nylon seal under the back plate with the screwdriver. Remove the nylon seal.
Locate the battery latch inside the watch and, with the screwdriver, apply light pressure to the spring that holds the battery latch in place. Remove the old battery and replace it with the new battery.
Close and seal the watch and follow the above steps in reverse to put the watch back together.