I've purchased a used Wii U a while ago. Today I tried to use it but I noticed it has a parant account and one child account on it. I can't access the parent account because it asks for a password. If I open the child account I can open a game but simple things like setting up a internet connection is not possible. I want to factory reset the device but cannot without the password of the previous owner. The owner doesn't response to any messages anymore. Wonder if there is a workaround or a guide to factory reset without parental access.