Handling the board by the edges, flip the logic board over to access the PRAM battery.

The PRAM battery is secured by a spring contact and two small plastic nubs.

On the side between the two plastic nubs (opposite the spring contact), gently slide an opening pick in between the battery socket wall and the battery.

Use the opening pick to slide the battery away from the two plastic nubs.

Once the battery's edge clears the two nubs, use the opening pick to tilt the battery up out of its socket.