Horrible job, will take the best part of a day to get the job done....
You need to remove:
Centre console, all switches/lamps (careful of the heater control lighting), wooden/plastic trim along the front of the dash, the AC cover under the left of the dash (or whatever is there if it is not AC), loosen the top of the dashboard, unbolt heater assembly (nuts are right on the bulkhead), disconnect heater hoses, and sort of man-handle the heater unit out, while cursing at the dashboard trying to spring down on you all the time.
Take 20 minutes to apply elastoplast to fingers, then:
Remove all clips from the heater assembly, disconnect the various linkages from the heater to the various flaps etc, split the heater in two, unbolt/screw the motor, and remove, replace with new one -drip or two of oil on the bearings if possible beforehand.
Put it all back together -being VERY careful of all the flimsy linkages, otherwise you will end up with a heater that doesn, for example, heat your toes, but is great at demisting the windscreen!
Refit heater box under the dash, and go about putting the rest of it back together...
come to think of it, I took about another two hours the next day replacing screws that I had put back in the wrong place.....
I don't envy you at all....
Bowie.
