Start with 0000 steel wool and Windex.

The wool won't hurt the image.

Scrub gently to loosen the crud and wipe with a paper towel.

You can also try some Prep-Sol with the wool if the windex doesn't clean it up enough.

The image is baked into the base glass. It takes a lot to remove the image. The crud is on top of everything.

Later . . .

Jim

[Linked Image from cruisin66.com]