Instructions
Turn on the Wii.
Pull open the Wii's SD card cover, located below the "Power" button on the front of the console. The Wii's sync button lies in the SD card bay.
Remove the Wii remote's battery cover, located on the back of the remote. The remote's sync button lies in the battery bay.
Press the remote's red sync button. It is the only red button in the controller's battery bay. This places the remote into pairing mode.
Press the Wii's red "Sync" button in the console's SD card bay. The Wii will search for nearby controllers in pairing mode. After a few seconds, the remote will automatically be programmed to the Wii console.