Changing your PIN is easy. Keeping it from your kids is the hard part:
 

1. Open the Menu
2. Select Settings*
3. From Parental Controls select Change Parental Control PIN
4. Enter your current Parental PIN. The default is 1234.  Forgotten your PIN?
5. Now you can choose your new PIN.
6. Confirm your PIN.

That’s it. Write your PIN down somewhere safe.

*Settings can be found via the cog in the top right corner of the Menu. You can get to the cog by pressing Up and right after opening the Menu.