With the four bolts out, the armrest is removed. | 
Several screws hold the ashtray and lighter portion of the center console in place. Remove those, thread the piece up and away from the parking-brake handle, and unplug the cigarette lighter and power-mirror switch. | 
Whether your car has the stock cassette-deck or an aftermarket head-unit, it needs to come out. Remove it from the center stack (usually accomplished by removing four screws), and unplug it from the speaker harness. |
At this point, we're ready to remove the console. Carefully pry off the shift handle and shifter boot, and remove all screws that hold the console in place. With the shifter in Second or Fourth gear, we just get the console up over the handle without breaking anything. Work slowly and carefully on these Fox-body interiors because everything is made of plastic and can break easily. | 
Remove the front screw on each sill plate so the kick panels can be removed from the footwells. | 
The HVAC control panel is unbolted from the dashboard by removing the four Torx bolts. Drop down the panel of three rotary knobs; it doesn't have to be unplugged and totally removed. |
The steering column is next. Four bolts are removed to drop it down from the dashboard. These two closer to the firewall near the pedals... | 
...and two more near the hood-release handle that also drops down with the column. | 
The plastic trim pieces from the column are also removed to access the gauge-cluster binnacle and the cluster itself. Unbolt and remove the housing as shown by removing the appropriate Torx bolts to access the gauge cluster. |
On '87-'93 Fox Mustangs, the cluster housing contains the switches for headlights (and foglights on GTs), emergency flashers, and the top on convertibles. Unplug all of these so the bezel can be removed to access the gauge cluster. If necessary, use a screwdriver to carefully unplug the factory harness plugs. | 
We've removed the gauge cluster by taking out its Torx bolts and unplugging it from the dash. These are the two plugs and the speedometer cable that are unplugged to remove the gauges. | 
Directly under the windshield is a plastic trim piece that must be removed to access the Torx bolts holding the dash in place at the firewall. Carefully pry it up as shown, being careful not to break it during removal. |
Under the trim piece removed in the previous photo, there are three Torx bolts that hold the dash in place. Two others are on the outside. | 
Finally! With the five Torx bolts out, the dashboard is separated from the firewall and dropped down far enough to access the heater-core/evaporator-coil case, visible here behind the passenger side of the dash up against the firewall. Getting the dash out of the way is a major hurdle, but we still need to get to the core itself. Luckily, this car is a convertible, which makes it considerably easier for us to shoot photos of the action. | 
With the dash out of the way, access the evaporator case (where the heater core is located) by unbolting the heater case from the firewall. The bolts are located at the bottom of the case as shown here. |