No Bug How can i' remove the mute hotkey

[unable to retrieve full-text content]

When trying to talk another user through the setup wizzard concerning microphone issues. I assigned the keyboard key "M" to the hotkey assignment for muting the microphone and cannot figure out how to return it to the original "No Hotkey Assigned". Now the setup wizzard is driving me nuts because... No Bug How can i' remove the mute hotkey