They make stuff for this, its a liquid that you apply that frosts the plastic. You use some vinyl, and cut the image out of the vinyl and apply the picture to the window. then you clean and peel off the vinyl to have your image. Another way is to just use vinyl, they have frosted clear vinyl u can use, that is also removeable later on.

neonblingbling you should of used a dremil, 100x faster.