Transfering PS3 Themes and Wallpapers to PC for Editting

Ok, so I adore some of the game related themes and wallpapers from the PSN Store. But I like my wallpapers for PS3 to have sort of, guide lines so I can more easily see the menu options (like in the Eternal Sonata theme). I'd like to get the Batman: AA theme's wallpaper, put it on my PC, then touch it up with those kind of lines. How would I go about doing that? Anybody know?

If it is one of the motion themes, that has movement in it, you can't... if it is simply a picture I think you can just put it on a flash drive or card and then put it on PC...

Read this how to make your own theme.

http://www.bestps3themes.com/create-ps3-themes-tutorial/