Trying to install Audiovox cruise - '78 300D

[rgnprof]

I have grown tired of fixing cruise amps and decided to install the Audiovox CCS100 in my '78 300D. This is the older 10 pin amp with the vacuum actuator. I have read through all the threads - including MaydayMike's thread.

I have the cable hooked up and I think I have figured out how to install the magnet on the driveshaft - my trouble is figuring out the wiring. I want to wire it in to my current switch - is this possible on the 10 pin amps? I have the wiring diagrams and I guess I made the mistake of reading thru the wiring instructions in the Audiovox manual - after reading thru Mike's instructions...

According to the manual, you have to connect the wires that run through the firewall to different wires at the brake switch etc. I am assuming that since my car already had cruise that I can connect to the wires at the point where my old cruise amp connects to the wiring that runs to the switch on the steering column. Right?

Has anyone done on this on the 10 pin systems? I got a little confused when Mike talks about taking a junk cruise amp apart and unsoldering the plastic end piece...