If you don't have the proper tools to remove the old HU, just remove the two screws behind the ash tray that hold the front trim on (were the vents next to cluster and inset).
Then pull from the bottom working your way across the trim piece. The aftermarket HU should come out with the trim piece, or there might be a metal plate it is attached too.
Then just bend the tabs that hold the HU to the trim piece/metal plate back, remove, and in stall the new one.
I have had mine out of my 92 many times.
P.S. If you have any questions just ask.
2013 Ford F-150 FX4
5.0 6-speed Auto/Manual 4x4
1992 Ford Ranger STX
4.0 5-speed 4x4
1987 Mercury Cougar
5.0L AOD 8.8
Last edited by DannyG; 09-25-2009 at 10:05 PM.