This is for a 2-item removal for the outside mirror and dashboard cover that lots of people have been asking about. Up first is the outside mirror, pretty simple process to do.
First you want to push the mirror all the way down, using your fingers is fine just don't push fast.
Second, you want to put your fingers between the upper lip of the mirror and the housing.
Third, just pull down. Be sure you have your other hand on the bottom side of it, other wise when the mirror falls it could hit the door. Also, be careful with the heating element wires if your CTS came with outside heated mirrors. They won't be any labels on the mirror indicating if they are heated or not. But from what I've been hearing, blue tinted, such as mine, are the heated mirrors. While non-tinted are non-heated mirrors.
Before installing, just clean up any debris that maybe in there. Also, you don't want to have the mirror off for too long. Because the mirror actually incloses the motors. As you can see in the pictures they look clean after so many years.
To install, just snap the mirror back in place. It should go on only one way.
Now on to the dash board...
For this you are going to need a large flat head screw driver. Or better yet a putty knife. I used the screw driver because I had mine off a few times and it's pretty easy now. It maybe a little harder for yours as it might of never been off from the factory. If this is the case, just go back and forth along the edge prying up little by little. It is press-fit into the car, so there shouldn't be anything to break.
Insert the knife at the edge. And gently pry upwards. Pull up little and move on the edge, pull up again and move along the edge. Repeat until the cover pop ups.
Once the cover has been popped up, you now have to remove the light sensor. Just turn it counter-clock wise. I believe that white piece, that is in the picture, stays on the dash cover.
Here's a close up of the sensor. You should be able to see all three of them. the two that are facing downward of the picture actually face forward and to the two sides of the car when installed. These are used by the HVAC to determine what side the sun is on. If the sun is beaming on to the driver, then the air coming from the vents for the driver will be slightly cooler than the passengers.
To reinstall the cover, just line up the holes in the dash with what is on the cover. You can see the tabs in the picture which has white tape on them. Those tabs gets inserted into the front most holes of the car. Which are facing you when you are in the seat.
Once they are all in, press evenly on the closest edge and just reverse the removal.
PS. For those of you who have memory seats, like me, you need not worry about any sensors. As they must be built into the motors. Because even after manually moving the mirror with your hand. It will move it back to your memorized position when you press the memory button.