1. Unplug the treadmill from the power outlet.
2. Locate the battery cover on the back of the treadmill. It is usually held in place by screws.
3. Remove the screws and lift off the battery cover.
4. Disconnect the red and black wires from the old battery.
5. Remove the old battery from the battery compartment.
6. Insert the new battery into the battery compartment.
7. Connect the red wire to the positive (+) terminal on the new battery, and the black wire to the negative (-) terminal.
8. Replace the battery cover and secure it with the screws.
9. Plug the treadmill back into the power outlet.
