My old Fire had a burnt in screen, so I contacted Amazon and they mailed me a new one. When I put in my account info on my new one after deregistering the old one, the new said "Zach's 2nd Kindle" but I didn't want it to.
Deregistered my old one, changed the Kindle's name on amazon.com, deregistered my new new one, restarted the device, and re-registered it. lol