Instructions
Place a game that requires the Wii Balance Board, such as Wii Fit, into your Nintendo Wii and start the game as usual using a Wii Remote.
Locate and press the red "Sync" button underneath the battery cover of your Wii Balance Board. The power light will start to blink.
Locate and press the red "Sync" button underneath the SD Card slot on the front of your Wii console while the light on your Balance Board is still blinking. Synchronization is complete when the power lights glow steadily.
Replace the battery cover on your Wii Balance Board.