I changed mine by taking putting my own bmp files in place of the NX120_BG_1.bmp wallpaper files in the CE66 2.45 firmware update file. So find the wallpaper you want in 800x480 format. Rename it to either NX120_BG_1.bmp or NX120_BG_2.bmp and replace the files in the wallpaper folder inside the firmware update. This is how I did it hopefully you can figure this out.