1. Turn off the piano. This is important to avoid any damage to the instrument.
2. Locate the battery compartment. It is usually located on the back or bottom of the piano.
3. Open the battery compartment. There is usually a small latch or screw that you need to loosen.
4. Insert the batteries. Make sure that the positive and negative terminals of the batteries are aligned correctly.
5. Close the battery compartment. Make sure that the latch or screw is tightened securely.
6. Turn on the piano. The piano should now be working properly.
Here are some additional tips for replacing the battery in a Casio piano:
* Use alkaline batteries. These batteries last longer than other types of batteries.
* Do not mix old and new batteries. This can damage the piano.
* If the piano will be stored for a long period of time, remove the batteries. This will prevent them from leaking and damaging the piano.
If you have any questions about replacing the battery in your Casio piano, please consult the owner's manual or contact Casio customer service.