You can assign or re-assign an owner to a user from the owner page. Or, from the owners' list, select the owner(s) and click on the bulk action and choose Assign To, and pick a user then confirm on the change.
How do I assign an owner to a user?
You can assign or re-assign an owner to a user from the owner page. Or, from the owners' list, select the owner(s) and click on the bulk action and choose Assign To, and pick a user then confirm on the change.