The Wii Nunchuk is an attachment for the Nintendo Wii console's remote. The attachment adds more options and mobility for gameplay with two additional buttons and a joystick. You can sync the Nunchuk by first attaching it to the Wii remote. You can then sync the Wii Remote to the console and use the attachment for any compatible games.
Insert the Nunchuk plug so that it fits and clicks when connected.
Press the "Power" button on the Wii console.
Remove the battery cover from the Wii Remote.
Find and open the panel that covers the SD card slot on the console.
Press and release the "Sync" button above the batteries.
Press and release the "Sync" button beside the SD card slot right after.
Wait for the blinking on the "Player" light to stop to confirm the synchronisation.