To delete a Geofence, you'll first need to remove the devices on the fence first.
Step 1: To remove devices from a Geofence, click on the Geofence's name to open its detail pane.
Step 2: Choose the 'Devices on Fence' tab. Click on the ellipsis (...) for each device and select Unapply.
The device's Last Action status should read 'Unapply'.
Step 3: Go to the Geofence screen. Click on the ellipsis (...) next to the Geofence's name. Then select Delete Geofence.
The Geofence will be deleted.