'87 GT--Removing Premium Sound Wiring?

Have you ever bought a car with options you didn't want? Well, I've been trying to piece together the factory premium sound system on my '87 GT. The car had been parted out when I got it, so I had to track down the graphic equalizer, the specific Premium Sound radio (try finding that one!).

The radio I found recently quit playing, so rather than keep dumping money into the stock sound system, I'd like to go with aftermarket.

My question is this: I seem to remember reading somewhere on the forum that the premium sound wiring will actually unplug somewhere behind the dash. Basically, if you find the plugs and unplug and remove the Premium Sound wiring, you're left with the regular radio connections that all of the non-premium cars had.

Does anyone have any input on this? I hate to tear my dash apart just to find that the premium sound wiring won't simply unplug somewhere.