1990 Cadillac Brougham Tuner/Amp Location

i have a friend trying to install  an after market kenwood head unit in this vehicle but has noticed he needs a tuner/amp bypass. i guess he'll pick that up but we need help on where is it located at? we can;t find it please help!

The tuner box on this car is located behind the vent on the drivers side of the piece that surrounds the radio.  I've done two of these cars in the past month and have done each of them differently.  The first one I tried to go from the bottom to unplug the harness and antenna (by the way it is a standart GM harness and GM antenna) after fighting and cussing it for about half an hour I finally got it unplugged, this was with the help of a co-worker pulling on the harness while I pressed the release clip.  The second one I had to do dash speakers as well as a deck, so I pulled off the top dash piece,  and noticed that the tuner was much more accessable this way, I then removed the wooden trim that has all the lights (seat belt, check engine, etc) that runs the length of the dash an was able to un clip the plugs and the antenna fairly easily, at least compared to the other way.  Just a heads up, the harness has three seperate plugs,  and you should have plenty of length to pull into the dash opening to wire up your deck.  Use the newer Double Din GM kit, and it should work great with the factory brackets.  Depth is a major issue on this car, so chose your deck wisely.  Good luck.