Remove the metal bar that holds the battery in place with a flathead screwdriver.
Take the cable ends off from the battery terminals with a battery terminal puller. Remove the negative cable first.
Lift the battery out of the compartment. Safely dispose of used battery at an auto parts store, which will often take it as a trade-in, or bring it to a recycling center.
Use a wire brush to clean the tray that holds the battery. Wipe it off with a damp cloth and let it dry before replacing new battery. Dispose of the rags that wiped off the acid.
Clean the insides of the connector cables with a pointed wire brush. Keep your gloves on at all times to avoid getting acid on your hands.
Place the new battery on the shelf. Put the correct cable on each terminal and tighten securely with pliers or socket wrench.