How can I change the identity name of my new iPhone 6?

I purchased a new iPhone 6 to replace an iPhone 5 with an expanding failed battery. I loaded the iPhone 6 from my iPhone 5 backup. In the process, the new phone picked up the name of the old phone. Every time I pair the phone with a Bluetooth device, that old name keeps appearing. For a variety of reasons, I wish to change the iPhone's identity name. How can I do this?