How do I delete an Apple Loop from the Loops Browser

I have added a MIDI loop to the loop browser that I don't want to keep.

How can I edit or delete these loops?

Every piece of advice I've found has been woefully out of date, either pointing me at a location which doesn't have the loop stored, referring to menu functions that Garagaband doesn't have, or telling me that the delete button will get rid of it (it doesn't, unless the full size keyboard has a delete button that works differently to the standard keyboard)