here's a link about the domain name change, not sure if it really helps you. Domain Name Change
As for Enterprise activation, you shouldn't have to delete the account. If you look at the user properties, does it show the correct domain? If not, then delete and re-add the user, set the password and activate.
To reset the device, just perform a wipe on it.
Mods - I think this would be better served in the Admin Section