Setting Default Delivery Device after User Device Import

I have successfully imported user devices and they show up under Manage Content > Devices but I do not know how to set the device as the default for the user. I have used the group subscribe and it works to add the subscriber but only those that have set their default receive the notification. On the others, if I have them log in, their default device is not set to anything. Is there a way to force these imported devices to be the default from the Admin perspective?