How to replace the heater/ac air blend door actuator

What is your question?

I have a 1994 Cadillac Fleetwood Brougham. When the weather is cold and I turn the heater temperature up to 80-90 F, to warm up the passenger compartment, the blower blows only cold air inside the car at the feet. The heater was water flushed and the flow was very good. When I turn temperature up or down, I do not hear the sound of any movement under the dash, such as the blend door opening or closing. I am surmising that the blend door or the blend door actuator is not working and need to be replaced. I have several questions: Need to know the exact location of the blend door and the blend door actuator, relative to something obvious such as the glove box or the radio location. I need to know the easiest way to get to the blend door/actuator, to see if the blend door is jammed, and if not to get the procedure how to replace the actuator. I need to know which parts have to be removed out of the way to get to the correct blend door/actuator, as I understand there is more than one actuator. So I need to be sure I am replacing the correct actuator. I need to know the step by step process on how to remove the old actuator and re-install the new actuator. If these procedure may affect or cause the Air Bag to deploy, I need to know what to do to avoid that potential.