the new one across the top of the contact, i figured out that i can just right click that bar with the category name in it and pick, for instance, clear food a-c since that's one of the old categories that i want to get everyone out of.
but then i discover that when i go onto my phone, on the people-groups page, i see both the new group names and the old ones. so i just go to food a-c, for instance, and then tap the ... and select delete which will delete the group but not the contacts.
so i did that to all 3 of the old groups that 