Step 6 · Remove the Old Air Gap Assembly (Optional)
If cleaning did not resolve the issue, or if you found the air gap body to be cracked or broken, you will need to replace it. Start by going under the sink and disconnecting both the smaller hose coming from the dishwasher and the larger hose going to the garbage disposal. Use pliers for the clamps and have your bucket ready. Next, unscrew the large plastic mounting nut that holds the air gap body to the underside of the sink. Once the nut is removed, you can pull the entire air gap assembly up and out from the top of the sink.