How do you unsync a wii fit balance board that is connected to two wiis?

SOURCE: my wii balance board wont stay on

First thing to do is install fresh batteries.If the Wii Balance Board is still experiencing power problems after trying new batteries and ensuring that they are inserted correctly, please call 1-800-255-3700 for assistance


http://www.nintendo.com/consumer/systems/wii/en_na/ts/balanceBoard.jsp

SOURCE: how can i re connect the wii fit balance board to

Synching can be completed only if a compatible game disc is running in the console. Compatible game discs (such as Wii Fit) will display the Wii Balance Board icon on their packaging.
The Wii Balance Board must be synced to each compatible game individually.
These sync settings will be saved even after the console is turned off.

Follow these directions to sync the Wii Balance Board (so that it is recognized by the Wii console):

Insert a Wii Balance Board compatible game disc (such as Wii Fit) in the Wii console.


Use the Wii Remote to select the Disc Channel from the Wii Menu, then select "Start" to begin the game.

Open the SD Card slot cover on the front of the Wii console.

Remove the Battery Cover on the bottom of the Wii Balance Board.

Press and release the SYNC button on the Wii Balance Board. The Power LED on the board will start blinking.

Press and release the SYNC button on the console while the Power LED on the board is still blinking.

The Power LED will stop blinking and light steadily once the synchronization is complete.