SentaiBrad said
If you are editing XAML files replacing images is not the best way to go about it, because then if you want those images for something else they'll then be replaced with blank images. I don't know what to edit if you are making a theme, but the replacing method if you want them to be replaced for yourself. If it's a theme you are making then replacing the banners may not be the best way.
I have to use the screen in the children's menu and must be equal for all games (eg all super nintendo games)