How do I get an OfficeJet Pro X476dw printer's admin functions are locked.

Since this printer has no physical buttons, but a touch screen display there is a special way to get into service mode

Right after applying the latest firmware upgrade on a brand new HP X476 printer, All of the admin functions displayed a padlock icon, they were locked and requested an admin password. Since I had just gotten the printer, got it networked, and all the preferences set, I had not created an admin password. The update assumes you had set it and locks all of the admin functions. So I had no password set, therefore there was no password after the update. So I could not do a reset as it is protected.
After over and hour with HP Support (his name was "Bob" with a very heavy Indian accent) I got them to "give up" the way to get into the service mode to do a hardware factory reset.
Warning: There are functions in this mode that are meant for service technicians and can cause major damage. We all like to "tinker" but I strongly suggest you stick to the reset functions only.
Start from the home menu on the printer's screen. Press the "return" icon. It is not illuminated at this point. You can display it by pressing one of the main icons (copy, scan, fax, apps) and mark where it is. Press it 4 times. The servfce menu appears. press down until you get the reset menu. Select the partial reset. That should reset the printer to factory defaults.