Sorry I don't know the image you're talking about, but the process is always the same. Find a copy of the image you want to use. Scan it into a graphics program like Photoshop-there are several good choices-alter it to suit you and print it to the decal paper.

Ahah, I found the web site I was thinking of:

http://modelinghints.homestead.com/Decals.html

Bill's site is full of good building help.