After our less-than-ideal entry into the device, we somewhat guiltily spy a hole under the battery compartment. Could this be the real way in?

We peel up a sticker and...

The access hole that would line up with the three screws holding the Dial in its shell has been plugged up!

Minus any mysterious methods Microsoft may deign to share with us, our best recommendation for opening your Dial is to drill through this plug and access the three screws using the above turntable method.