Devices can be unassigned so it can be reassigned to the proper person.
How to change device assignments
Open the Network page and select the Devices tab.
Select the device from the All devices list.
Tap the Options button on the top-right of the device's details screen.
Choose the Unassign option from the pop-up menu.
The following step can be skipped if you want the leave device unassigned.
Tap on Assign to a profile.
Select the person or group you want and tap on Assign.