'87 5000cs door lock - replace?

[tom winter]

Hi All: 
My God, it must be the cold weather here in Colorado! But a couple of days
ago my throttle cable snapped and now this. . .

I've searched the archives and found some mention of this problem, but no
BTDT on repair/replace (although there was a suggestion to replace door
handle/lock w/o particulars on the proceedure)

The driver's side door lock now spins and won't lock or unlock the door. Of
course, passenger side still works and the car in question is an Avant, so
if passenger side fails I can still crawl in and out the back.

I'm in need of directions on how to access the guts of this lock and advice
on if it's possible to repair it or if I need to replace with a new lock.

Thanks in advance and once it warms up enough (1.7 degrees F at my house at
7am this morning) I'll tackle the job.

Tom