I don't think you can, but I'm not a 1200% sure on that. I don't think I'd try. You might take a shallow bowl and put a little naphtha/lighter fluid in it, just enough to cover the chrome ring and set the hood in it. Let it soak for a few hours and then take a tooth brush and scrub the inner rings. Do this several times until you're satisfied it's clean. When you are all done put the tooth brush back in your wife's side of the rack so she'll have a nice clean tooth brush for in the morning. She'll really thank you for that.