Tile layer is a program originally for DOS. Although recently re leased in windows. being able to take a rom file and show you all of the graphics that game uses. those graphics could be altered flipped or switched. it also has a nifty feature to open 2 roms at a time. so you could take graphics from one game and throw them directly into the other.
Easy. simply download the zip file and run it. go to the file tab and select open. open the rom you want and Voila.
you can download it here at Zophars domain