I agree it's a big job.  It took me the better part of a morning to do the
whole job.  However, with your dash all apart, it is a good idea to take a
look around for other broken wires and broken lever cables and such.  I
found it an excellent opportunity to clean all the dust that had
accumulated under there.

However, I have to say that I was quite lucky in that my blower had been
apart before, so someone had used screws to hold the heating lever plate on
and to bolt the heating unit back together.  Therefore, I didn't have to
break open the heating unit through all the tabs which saved a lot of time.

One particularly frustrating moment will come when you actually have to
take the heating unit out.  I discovered the big screws like to get frozen
in there.  There was also a screw that had to be taken out through the
front grille.  I'm not sure if that's supposed to be there or not.

I guess if you have a lot of patience and a lot of tools I'd suggest doing
it yourself.  There are a lot of other things you can check while you have
the whole dash apart, and there are a lot of plastic things to break if
you're careless or your mechanic is careless.

-Mike