Astro 320 update

I've read so much information here.

I'm a little bit confused. Is there a difference between software update for the device and the firmware update?

Is there a tutorial that explains how to update the Astro 320 US. And that it will be useable in the EU?

And when you update the device, you need to update the DC 40 collar? How to do? Is there also a tutorial?

Thnx!