First of all I would like to Thank TitanTX Pro4X for the excellent post with pics concerning the Possessed WoodPecker noise behind the dash, plus I would like to provide a link to his thread to be used with this Armada specific thread. With the help of TitanTX's thread and a mechanical inclination I was able to complete this task in approximately 1.5 hours.
Below I have also provided the link to pics of the components I removed to get to the lower actuator on my 06 Armada LE. Can't say that all Armada's are the same throughout models and years, but they should be close. Upon comparing my Titan LE to my Armada LE I noticed that access to the actuator on the Titan is much easier.
Pic 1: Start of the project.
Pics 2 & 3: There are two screws that secure the plastic cover below the steering wheel. Remove them and pop the panel off then disconnect three or less plugs on left side if applicable.
Pics 4a & 4b: Remove plastic heater panel on rightside of drivers seat. Remove metal plate held in by 4 bolts underneath the steering column. Plastic heater panel is removed by giving it a nice tug at the rear of it then slide it toward rear of vehicle.
Pics 5 & 6: Gas pedal assembly. Removal of the two 7mm screws will allow the pedal adjustment motor to be removed. Don't forget to remove the small cable (Gold in color) between the motor and the gas pedal assembly. It will fall out and is easily lost as the gas pedal assembly is removed. Without it the pedal adjustment feature does not function for the gas pedal. Three nuts hold the gas pedal assembly in place. Two on top and one on the bottom. Be careful the nuts like to fall and hide underneath the carpet.
Pic 7: The components that blocked access to the actuator assembly on the Armada LE.
Pics 8a & 8b: Four 10mm bolts hold the bottom component on. Remove them and the one component to gain access to the two 10mm bolts that hold the remaining components in place. I discovered that unplugging the blue plug made it easier to slide them down past the upper screws where the gas pedal mounts. Once removed it can be hung conveniently out of the way on the center console.
Pics 9 & 10: I used a flat head screwdriver placed between the mounting plate and the white cam gear to hold it in place prior to removing the actuator and while it was removed. The actuator can then be rotated until it lines up and slides in. Remove screwdriver then rotate actuator until the top slot is aligned with the tab next to the upper screw hole. Slide it over the tab to hold it in place while the screws are installed.
With actuator replaced, re-assemble the dash components in reverse and the Possessed Woodpecker exorcism is complete. My wife wanted to let the stealership repair it, but once she got the estimate of $350-$400 plus the cost of the part she was convinced that the do it myself program was the way to go. I knew she would see it my way.