I did the instal myself in my 2004 Thunderbird. Radios and More provides the
proper instructions for a vehicle along with the receiver.  In fact, the guy
at Radios and More sent me the instructions before I bought the receiver. It
was realtively easy in my case. Some people ignore the instructions and
install the antenna on the dash. This saves a lot of work.See
http://www.radiosandmore.com/ .

Ed

  I just installed the radio, satellite receiver, and satellite antenna
on my son's 95 Explorer.  Since you already have the "Sirius Ready"
radio you only have to install the satellite receiver and run the
wire up to dash.  Satellite ready only means your head unit will
accept another source, namely a satellite unit.  Ensure the cabling
from the satellite receiver to the head unit uses a compatible
connector.  I placed the receiver under the larger rear seat, bolting
it to the floor.  The antenna must be outside.  I hot glued it right
at the center back, routing the wires in the hatch back molding.
Mark  

The factory kit is labour intensive... satellite receiver and antenna go in
the back. It gets worse if you want to be sure there's no new squeaks and
rattles after you're done. I only did one..... if they ask me to do another
one, I'll run out back and hang myself...