You can set the administrator password using Web Config. When using Web Config, it is necessary to connect the printer to the network. If the printer is not connect to the network, connect the printer's LAN port of the standard or the additional network to the computer with an ethernet cable directly.
Enter the printer's IP address into a browser to access Web Config.
Enter the IP address of the network (standard/additional) you want to configure from a computer that is connected to the same network as the printer.
You can check the IP address of the printer from the following menu.
Settings > General Settings > Network Settings > (Standard or Additional) > Network Status > Wired LAN/Wi-Fi Status
Enter the administrator password to log in as an administrator.
Select Log in, and then enter the administrator password, and click OK.
Select Product Security-Change Administrator Password.
Enter a password in Current password and New Password and Confirm New Password. Enter the user name, if necessary.
See the related information below for the default of administrator password.
Select OK.
To restore the administrator password to the initial password, select Restore Default Settings on the Change Administrator Password screen.