if you prefer a video, in this video you can see the tutorial under 42 second!
Step 1: Use the Heat!
the hairdryer can melt the glue under the stickers and you can remove the stickers easily.
Step 2: The Annoying Glue
For remove very easy and fast i use a element of recycling of your kitchen...the oil :)
Step 3: The Miraculous Oil
i use a waste oil from the kitchen, so you can give of the oil a new life.
the power of this trick is because the oil reduce friction and the glue on the glass is easily removed, you need only a napkin or a sponge and rub on the surface you want to clean .
if you have a problem you can use "hot oil" but be careful not to burn yourself...remember, the glue and the stickers don't like the heat!