Remove Old Printer from iPad Pro

You don't add or remove printers from an iPad.

Printers appear in the AirPrint dialog automatically. If its showing up there, then it means its on the same Wi-fi network as the iPad, turned on and ready to print. The only way to make it not show up on the iPad, would be to turn it off.

AirPrint is a driverless printing technology so there is never anything to install or uninstall. Air printers on the same wifi network your device is connected to will simply appear and be available to you.

Active AirPrint printers “advertise” print services to the network to which they are actively connected. Network discovery protocols discover printers that advertise print services - and these printers are then listed in the print dialogue of your iPad and similar devices.

As soon as an AirPrint printer is removed from the network, it will be removed from the list of available printers.