These instructions are on how to remove the factory stereo and install a Pioneer DEH-P6300 on a 1987 Ford Mustang:
(1) Buy the removal tool and wiring harness from walmart (about $10)
(2) Before trying to use the tools and remove the stereo you have to remove a wire that is latched onto the base witch holds the stereo in.
It's a metal wire that is connected from the back of the stereo to the side of the compartment by a little black clip.
(3) After you remove the clip pull the stereo out as far as you can and unplug both wires and the antenna wire.
(4) Ether disconnect or completely remove the premium sound amp.
It's shaped like a little football and is right behind where the stereo was.
This is where it's located on 87's. 88 on up is under the seat.
(5) Now for the new CD/Cassette player.
The new deck isn't going to plug into where the old one did.
The cords your looking for are actually up behind the heater/ac controls.
They will match right up with the wiring harness once you get to them and disconnect them from the factory plugs.
NOTE: to make step a lot easier unscrew the heat/ac controls to make a lot more room/visibility
Hope this saves people a lot of time.
Thanks for all the help: