There is a script for reverting the Call UI included in this zip file. If you can't run that for some reason, then just type:
devel-su
to become root, then copy the original call ui backup file to it's original place. If you don't know how, just read the command in the script.


On the topic of the updated UI itself, I think it's neat, but the extra large size of the caller picture pushes the red "End call" and the menu option buttons off the bottom of the screen.

Perhaps we could reduce the caller image size a bit and split the difference?