Place a towel in the bottom of the kitchen sink for a soft surface for the stuck glasses.
Put the glasses on top of the towel and pour ice cubes and a tablespoon of salt in the glass. Turn the cold water faucet on low and fill the bowl to the rim. Allow the ice mixture to sit for about five minutes.
Fill the sink with hot water until it reaches the outer rim of the glass. Turn the water off.
Put a little liquid detergent around the outer rim of the inner glass. This is the glass that is stuck inside of another one.
Allow the glass to sit for a few minutes. Grip the inner glass and pull the glass out of the bottom glass.