Edit or Delete "Groups" in Sprints

Edit or Delete "Groups" in Sprints

I cannot locate how to edit or delete "Groups" in Sprints Project section Default Section. Where is this list stored? New user and I created a duplicate Group with an identical name, and want to revise the name of another Group. It is not under Custom Layouts and Fields/Projects. It is also not in any menu I can locate within Project Settings.

This does NOT refer to User Groups.

This does NOT refer to Projects App. The method to change Groups in the zProjects app is not similar within Sprints.