hacker , you can use S1fwx to extract and repair your current firmware, guide here
http://www.mympxplayer.org/how-to-ex...tool-vt66.html
Next, using the repaired firmware (keep a spare backup as well), you can use S1res to theme the firmware, guide here
http://www.mympxplayer.org/how-to-mo...ool-vt206.html
There are many theme packs that you can download from the downloads section. However, you'll need to manually change each image individually in your firmware. You might also need to resize some images to match your original size.
Once you have themed your firmware and saved it, you would need to flash it back into your player, guide here
http://www.mympxplayer.org/how-to-up...ayer-vt46.html
Do note that you Must Always use your own extracted firmware to theme and flash into your player. Never use someone else's themed firmware to flash into your player as you will 99% likely to brick it.