Stereo Install Help Needed..., Help! Options

[twofoldjunk]

Hey guys,

Well, I tried to install a head unit today. Failed miserably. Could use some help.

Bought this unit:
http://www.bestbuy.com/site/Sony+-+Xplod+5...p;cp=1&lp=1

Sony Xplod 4x52W unit.

Tried to follow the instructions on the recommended threads:
http://www.6gc.net/forums/index.php?showtopic=22434
http://www.6gc.net/forums/index.php?showtopic=60939

Ran into some issues.

First, my car is a '96 GT. It has an amplifier. I have purchased a wiring harness from Best Buy.
According to the instructions, I have to pull the wires to the amp out to connect to the radio. The problem is that I cannot figure out which wires go where.

I removed the OEM stereo. There was a set of wires leading from the stereo to the amplifier. From the amp, there were two sets of wires leading to the vehicle/speakers. One set fit the harness, the other, I have no idea what it does.

I've spliced the wires from the stereo to the harness and attached the harness to the wires coming from the car. Unfortunately, it's not enough. There are wires that lead to the amp that aren't connected to anything and the second plastic wire harness in the kit isn't attached to anything.

So, I need help. How the hell do I get this stereo wired up?