How can I reset a used My Cloud withour the previous owners Username and Password

We bought a building back in March 2015 and the previous owner left a My Cloud. I hooked it up and it shows up on my computer with the previous owners info. I want to reset it to factory settings, so I looked up how and it sent me to open the dashboard. When I go to the site to open it, it has the previous owners name and asks for a password.
Obviously I don’t know their password and I can’t get in contact with them, is there a way I can completely erase everything without a password?

Do the 4secs reset