Instructions
Turn on your Wii and TV.
Select the "Wii" icon, then press "A."
Choose the "Wii Settings" icon and press "A."
Select "Parental Controls" under the "Wii System Settings 2" menu. Select "Yes."
Enter the PIN, then select "Change Settings" and opt to change your PIN. Click "Settings Complete" to save your settings.
Choose "I forgot" if you don't know the PIN. You will have to answer a secret question. (The answer will be case-sensitive.) If you have the correct answer, you can enter a new PIN. If you don't, you will have to call Nintendo at (800) 255-3700.