How did you do it?
Like where are the graphics located and how would I take modified ones and add only those modified ones back to the system?
Resuming:
1.- Copy SystemUI.apk and framework-res.apk from your tablet to your computer.
2.- Extract them using 7.zip.
3.- Browse the extracted folders searching for .png files and modify them as you like (be carefull with .9.png)
4.- Once you have edited the pngs OPEN the original apk with 7zip and REPLACE the files inside it with the ones you modified (check the correct path).
5.- Replace the apk in your tablet.
I have used GIMP as image editing software
I have not yet replaced my framework-res.apk. I'm still editing the battery icons.
I'm newbie with this stuff so not 100% sure about how all this work. And as everything esle, do it at your own risk!
Take a look at this article, it's for the Xoom, but both are androids aren't they?
http://www.xoomforums.com/forum/motorola-xoom-themes/4786-guide-how-theme-your-xoom.html