To rename a barrel group you will first need to locate it, under Winery Setup > Vessels > Barrel Group. Here you can see a list of all your barrel groups. This list will include the group, capacity, number of barrels, and the location of the barrel group.
Before editing make sure the barrel group is correct. There may be multiple barrel groups with the same/similar name.
Once you click on the barrel group, you will have the ability to update the Barrel Group Code, Area, or Bay. On the top left of the Barrel Group page you will see the Barrel group code. This is where you will put in the new barrel group name. Click Save to update.