Here'* the pics. You can see the air mix door arm through the left hole in the black steel dash structure with the inner glove box piece removed. The door can be moved by using a long screwdriver or similar tool between the steel part and plastic duct.
The manual calls for dash removal to replace the actuator. This is what I did to replace mine. Since then, there have been a couple of members here and on AF that have replaced them from under the dash by removing the heater core cover. It is possible and less time consuming than removing the dash but is more difficult because of the placement of the actuator and electrical connectors.