How to Replace a Garmin Forerunner 305 Battery
- 1). Turn the system over to find the circular battery cover (marked "CE").
- 2). Insert a small thin object, such as a coin, into the battery cover slot. Turn the object counter-clockwise to unscrew the cover.
- 3). Lift the battery out of its mount with your fingernail (don't poke or pry the battery out with a hard object because that could damage it).
- 4). Put the new battery in the battery compartment, with the positive sign (+) facing the circular battery cover.
- 5). Re-attach the circular battery cover. Use the coin to tighten the cover by turning it clockwise.
