Renaming bluetooth device on iPhone X

A couple other questions related to renaming bluetooth devices (https://discussions.apple.com/thread/8450103?answerId=33603543022#33603543022) all have the same answer of basically, "It can't be done". But I'm adding a screenshot of my BT devices and their respective names. I've apparently changed it in the past to "MattyBeats Studio". How did I modify it before... and how do I change it again?