from the service manual :

1. Remove the lower instrument panel cover from the instrument panel
2. Disconnect the blower motor electrical connector from the relief in the blower motor door.
3. Slide the blower motor door catch mounts to the sides.
4. Swing the blower motor door down.
5. Remove the screws attaching the blower motor to the heater housing.
6. Remove the blower motor and squirrel cage as an assembly.

NOTE: You can also see the top of the fan by removing the plastic cowl piece ( where the windshield wipers are )
This will allow you to go in with a vacume cleaner and remove all the debris ......