In this tutorial, you will learn how to reset your Wii U console to its factory settings. Please note that by doing this, all of your saved games, user profiles, and custom settings will be deleted from the console.
How To Reset Your Wii U to Original Factory Settings
Start your Wii U and tap on the Settings icon (the wrench) of the Wii U gamepad. The System Settings menu will be displayed.
Next, go back to the WiiU gamepad and use the left stick to move to the Delete All Content and Settings section. Press A to select. If you have enabled the Parental Control feature, you will be requested to enter your PIN.
Click on OK, and then tap on Next > Delete Everything to complete the reset.