Unfortunately that functionality is not in place for that owner. When you add a co-owner, they are on the team until they are removed.

I see you're the commissioner, so you can remove the team and then just re-invite the one owner you want:

Go to League>>Settings>>Remove Owner/Delete Team -- click the owner

you want to remove and provide a reason. You can then return to the

league standings and select "invite new owner".

If you click it once, it will only remove the owner, not delete the

team. If you go back and hit that button after the owner has been

removed, the team will delete.