Apple Configurator 2 can rename iOS devices. To use Apple Configurator to rename a device, first plug it into a Mac running Apple Configurator 2.
From Apple Configurator, right-click on the device and choose Device Name… from the Modify menu.
At the “Rename device” screen, enter a new name for the device and click on Rename.
Alternatively, you can use the (+) menu to choose variables to use during the renaming process. Here, you can choose to base a name on a Serial number, the Number, the device Type, or the Capacity of the device.
Once you enter new information, click the Rename button to change the name of the device.