How do I unbind keys?

Hi all,

I'm new to sim racing on PC and just installed SH (moved over from console).  I downloaded the Lovely Dashboard and have been tinkering with it in ACC.  I figured out how to bind keys on my Fanatec McLaren wheel in order to scroll through the different data points in the four zones of the screen.  However, now I'd like to change the keys but can't figure out how to do so.  The keys that have not yet been configured have a 'Click to configure' link next to them.  However, the keys that I bound have number range widgets in the link's place.

I'm likely missing something simple, but any help would be appreciated.

Taco