It's important to be patient when you're attempting to remove adhesive from glass. First, clean the glass with glass cleaner or white vinegar, then dry it with a clean cloth. Next, create a mixture of warm water and a couple of drops of dish soap. Allow adhesive to soak in this mixture for about 30 minutes, then use a clean rag to wipe the adhesive off. If there's any residue left, repeat the process again to remove it.