Ok. Now the first thing to take note of is whether or not a theme will match your screen size. That theme looks like it's for a 1.8 inch screen. Although it's intended for an 'Actions' chipset player i don't see why you couldn't import those images into a rockchip if it's the same screen size.
The second thing is just a word of warning. Although the firmware included on the disc appears like it belongs in the player, there has been a few cases where it turned out not be. So only proceed if you're absolutely sure it's the right one.
This program >
http://www.mympxplayer.org/logodiy-engrar-df564.html should be adequate to theme your players firmware. There is also a guide here >
http://www.mympxplayer.org/guide-roc...odd-df597.html
Just make sure the theme matches your screen size otherwise it'll end up looking like a mess.
Good luck