For Windows users
Open the printers folder.
From the shortcut menu of the printer with the new ISP, open the printer properties.
Configure the port from the list.
Update the IP address.
Apply the changes.
For Macintosh users
From System Preferences in the Apple menu, navigate to the list of printers, and then select + > IP.
Type the IP address in the address field.
Configure your printer and computer so they can communicate after installing a serial port on your printer.
Connect your printer directly to an active telephone wall jack or share a line with an answering machine or voice mail service.