My cas wires have spilt around the rubber grommet. Anybody have any advice for running new wires inside the cas?

 

Use the same size and length of wire, mark the locations of the sensors before you remove them, and check their clearance to the wheel with a feeler gauge before disassembling. Also mark the wires before you cut and I would recommend solder and heat shrink. Obviously re-check them per the FSM spec with a volt meter and re-set the timing when you're finished.

 

or perhaps find a used CAS?

 

^This, much easier than trying to fix it. A used FC CAS is pretty easy to find and won't cost you much.