Apply a small amount of jeweler’s rouge to your lamb’s wool cloth. Jeweler’s rouge is a polishing compound used to buff jewelry to a shiny finish without scratching or cutting it.
Gently rub the graffiti with your cloth using a circular motion. Check your progress often, and rinse the glass when the graffiti has been removed to your satisfaction.
Rinse your glass with a soft sponge soaked in a solution of 2 oz. of ammonia and 2 oz. of water.
Call a professional glass company if you can’t remove the graffiti with this method. Hang a poster or other object over the offending graffiti to conceal it while you wait for a professional to fix it.