in your "readme"file what do you mean by replacing set "Android FM Radio BG.png" as your FM Radio background, how? please help?
Place all those images into your pictures folder. On your Dingoo, open up the image and press the a button. A menu should pop up. Choose "FM radio background pic" for the FM radio one, "Music Background Pic" for the music one, and "E-book Background Pic" for the text-viewer one.
Note: To show the changed background for the text-viewer, open up a text file on your Dingoo and press the a button. A menu pops up. Choose "Background set" -> "Picture". Now the background for the text viewer should change.