anyone know WHERE this tweak is installed? (it replaces the signal strength icon in the status bar)...
It has two files in /Library/MobileSubstrate/DynamicLibraries/ and a bunch of images in /System/Library/Frameworks/UIKit.framework/
Bars doesn't replace or change any system files. Everything is loaded at runtime.
I don't understand your question.
The image files Bars uses are in /System/Library/Frameworks/UIKit.framework/. Apple's image files are packed away in an artwork file and cannot be easily edited.