Replacing the dash in a 944 is not overly difficult. However, it is very tedious and a lot of patience is required. It's going to take a lot of time but, don't let that discourage you. Work slowly, bag and mark all the fasteners, take lots of notes and pictures (to remind you where stuff goes), and you'll do fine.
Tools
Metric Wrench Set
Metric Socket Set
Screwdriver Set
Paint pen, colored nail polish, or other permanent marker
Dash Removal
Disconnect the battery negative lead.
Remove the steering wheel as follows:
Remove the horn button by pulling on the horn button pad in the center of the steering wheel. It may be difficult to remove so, you'll likely have to give it a pretty hard tug. There's a wire attached to the back of the button pad so, don't just go yanking the thing as hard as you can or you'll break the wire.
Once you have the button pad off, disconnect the wire attached to the back of the pad.
Using a 15/16" (or 24 mm) socket and ratchet remove the steering wheel retaining nut and washer.
Using a paint pen, nail polish, or other permanent marker, mark the orientation of the steering wheel to the splines on the end of the steering column shaft.
Remove the steering wheel by pulling it straight off of the end of the steering column
Under the dash, disconnect the three plugs for the turn signal switch, wiper switch, and ignition switch.
Remove the screws (4) that hold the turn signal / wiper switch assembly to the steering column and remove the assembly.
Remove the 6mm Allen head bolt for the ignition switch underneath the steering column.
Remove the long plastic spacer from the steering column followed by the ignition switch.
Remove the plastic trim piece from the steering column.
Remove the instrument cluster as follows:
Remove the two screws at the top of the gauge cluster.
Pull the cluster out enough to reach behind it and disconnect the speedometer drive cable.
Pull the cluster out further and disconnect the three electrical connectors from the back of the gauges.
Remove the cluster and store it where none of the gauges can get damaged.
Remove the center console as follows:
Remove the two screws that hold the instrument panel, remove the panel, and disconnect the plug for the instruments. Lay the panel aside so it doesn't get damaged.
Remove the radio and disconnect the wires from the back of the radio.
Remove the faceplate for the heater controls. It snaps off. Then remove the two screws that hold the controls to the console.
Remove the gearshift boot and move the gearshift lever back to give you enough clearance to remove the console.
Remove the six bolts/screws that hold the console in place. There are two large hex head bolts under the ash tray, two in the top of the console going into the bottom of the dash, and two on the side of the console.
You should now be able to remove the console by sliding back toward the gearshift lever.
Remove the glove box. Disconnect the glove box light connector as you slide the glove box out of the dash.
Remove the speaker grill in the center of the dash by prying up on the bottom of the grill.
Remove and disconnect the speaker.
Behind the speaker opening, you'll find a nut that holds the dash to the body. Remove this nut.
Remove the center and side vents from the dash by pulling them straight out.
Remove the tray under the dash in the passenger's footwell (3 screws).
Remove the trim panels on either side of the roof.
Remove the sun visors.
Remove the A-pillar trim pieces.
Remove the screws behind the A-pillar trim which hold the top of the dash.
You should now be able to slide the dash out of the car.
Installation
Maneuver the dash into position against the firewall and install the outside screws at the A-pillars.
Slide the glove box into the dash and attach the wires for the glove box light. Secure the glove box with retaining screws.
Install the nut in the speaker enclosure that holds the dash to the body.
Reconnect and install the speaker and grill.
Install the center and side vents into the dash.
Install the tray under the dash in the passenger's footwell.
Install the center console as follows:
Position the center console under the dash and secure using the 6 retaining bolts/screws.
Install the heater controls to the console (2 screws).
Attach the heater control faceplate.
Attach the wires to the instrument panel and secure panel to the center console.
Install the radio into the console.
Install the ignition switch and turn signal / wiper switch assembly onto the steering column.
Attach the electrical plugs to the switch assemblies.
Install the instrument cluster into the dash attaching the three electrical connectors and speedometer cable as you slide it into the dash.
Install the instrument cluster trim piece.
Attach the A-pillar trim, sun visors, and roof panel trim.