Pretty easy.

- remove the passenger side carpet
- remove the passenger kick panel (rearward then inward)
- remove the lower dash panel (3 screws in the carpet under the dash, possibly 1 screw near the kick panel, 1 plastic quarter turn screw in the carpet where the panel meets the tranny hump. The black plastic panel that continues to the firewall comes out with the lower dash panel
- remove 3 or 4 screws and 1 or 2 clips around the lower blower panel
- lower blower panel, watch out for the wires. Might have to unplug the connector just to the left of the blower case
- disconnect 2 wires from the blower motor. No need to mark; one's male, one's female
- remove 3 screws around the blower frame
- lower the blower motor and cage

Don't lose or move the balancing clips on the cage if you intend to reuse the cage.

You can get a replacement motor alone or with a cage.

If you get just the motor, press the cage off the motor, rather, punch the motor shaft off the cage. Be careful getting when getting the cage on the new motor that you support the other end of the shaft and the motor case so you don't damage the bearings.

I remove the glove box so I can properly fit the side vent to the duct.

Sixto
91 300SE
87 300SDL
83 300SD