Like Don said, it's the heater blower motor and it's located in the lower middle of the dash. No simple way about it, everything you're staring at has to come out.
Don't be afraid to run the motor as long as the circut is still fused properly.
If it howls on the high setting, then run it on another setting until it deep sixes itself. I have tried to inject a little oil on the bearings, but by the time you get to them, you're have ways into the damn thing. Not a difficult job, just long and tedious with many shortcuts if you know them. Plan at least a day, twelve pack of your favorite brew, stanby wife or girlfriend for when piss the current one off, and a large assortment of expletives. Oh yeah, lots of scraped knuckles too.

Sources of good info are the FAQ's on the BrickBoard, Sewdish Bricks, Bentley manual, and last but not least..old Don himself.