I found this thread pretty helpful, but I just had to remove this actuator on my 2007 V6. I found that, despite that top screw being EXTREMELY difficult to get to, it's possible without breaking any plastic or cutting anything. You are going to need some interesting combination of tools, and a buddy to help. That is if you're going to do it like me and my dad did.
1. Firstly, I removed the dash trim covering the instrument cluster like stated before in this thread (it just pops out with clips), and unscrewed and removed the instrument cluster (which comes out with 4 screws). From here, you can look inside and see the problem actuator to the right. The top screw, the one that is difficult to remove, is up and behind the large round air duct that connects to the left-most vent.
2. What you're gonna do want to do is, prop up that big air duct. Using rags, shims, or a combination of the two you want to prop it up against the metal frame bar that is right under it. Doing this will let us squeeze a socket onto the head of the top-most screw. If you don't prop up the duct, it will literally be touching against the head of the screw, and you'll never be able to get any tools up there. Trust me. Don't worry about breaking the air duct, we jammed it pretty hard up and didn't break ours. It apparently can take some tough force. So whatever you need to do to make room for tools against the screw head, you're pretty much ok to do.http://i.imgur.com/mJ60VCt.jpg
3. Go ahead and crawl under the dash, on your back, look up, and using your right-hand and a 5/16ths socket and a ratchet, unscrew that bottom screw of the actuator. This is the easy one. Also, if you haven't already, disconnect that wiring harness from the actuator. To do this, grab the small red clip pull backwards, opposite of the actuator, towards the direction of the wires, and then unplug the connector.
4. For removing this top screw. We used an funny combo of tools. What we did was, attach the 5/16ths socket to a bendy extension, then to a screw driver. Doing this allowed us to connect the socket to the head of the screw, and not have to worry about having room for a regular ratchet up inside the dash.http://i.imgur.com/j1GJ0n5.jpg
5. Now, for us to get this to work, I laid on my back with my feet hanging out of the car and my dad sat on the drivers seat at the wheel. What I did was, reached up behind the dash to the head of the screw, oriented our tool onto the head, and held it in place and applied downward force to make sure the socket stayed on the head. This was no easy task, and often the socket slipped off the head and we had to start over. As I held the socket in place over the head of the screw, my dad had the screw driver end of our tool sticking out towards the steering wheel, and he loosened the screw out. http://i.imgur.com/pCgueul.jpg
6. Once we got the screw out, we replaced the actuator and just reversed out process. I screwed the screw back into place by hand enough so it wouldn't fall down onto my face. Then I guided our tool back onto the head and my dad tightened the screw. Make sure the screw is actually going through the actuator into the mounting hole. Because I couldn't see the screw or the hole from where I was on my back, we ended up screwing the screw just into the hole without slotting it through the actuator, so we had to back it out again and put it back in AGAIN.
Your biggest enemy is the air duct. It's in the way of getting any long tools in parallel to it. Propping it up gives us just enough room to get tools onto the head of the screw, but this is only way we got it to work. I was down on my back while my dad unscrewed the screw because I had to actively press the socket tool onto the head of the screw and press up against the duct even more to ensure the socket stayed on the screw. It was pretty exhausting heheh. But holy frijoles it was satisfying once we got it all in the right way.