2003 Mustang GT Convertible Install

This forum was reccomended to me by a member of the Home Theater Forum.  I'm hoping for some basic information to help get me started on upgrading my stock Mach 460 system.

I need to know things like how to get the factory head unit out.  Ford used to use the systems with holes in the front, but mine doesn't have holes.  Also, I need to know how to get the door panels off and, if possible, what kinds of speakers will fit there and in the back.  I had a 2000 F-250 extended cab truck previously, and I installed two sets of Focal 165mm seperates with adapters I built for the factory 6x8 holes.  However, I am getting mixed messages on exactly what the factory size is for the front and back speakers.  Some say 5 1/4" front, 6 1/2" rear, some say vice versa, some say both 5 1/4", and some say both will take 6 1/2".

Ideally, I would like to buy a manual that would show me how to take all the interior apart, so I can measure things myself for fit, and install the equipment I want.  I have thus far assumed that the same wiring harness that I used for my Superduty truck will plug into the Mustang wiring harness.  If not, it shouldn't be too much of a challenge to find the right one.  That's not as much of a concern as making sure the Focal Utopias I want will fit before I buy them.  I have looked at Amazon for a manual that covers 2003 Mustang convertibles,  but have so far come up empty.  Ford shop manuals are probably overkill.  Can anyone point me in the direction of a good, affordable manual?

Thanks for the help.

Buzz