If you folks have any questions about the car please feel free to email us. One question I did have - when you replaced the Alpine with the Kenwood head unit, did you also have to replace things like the satellite radio and/or GPS antenna? If so, how hard was that?
Start at post 31. For the most part, you need to pull the HU surround off which is held in by four tabs that don’t want to let go. Look at the photos in that link to figure out where the tabs are so you can focus where you pull. Make your way around the surround one clip at a time starting with the two closest to the steering wheel. It helped me to use trim removal tools for the first two, the next two I just used my fingers and had to be brave. The buttons and hazard lights all have plugs on the back; disconnect those and set the surround to the side.
There are four Screws that hold the HU in place. Remove those and pull the HU right out. This may take some wiggling but they are the only things holding it in. You should find everything you need from there if your project is to only look at the back of the HU. There are a lot of wires back there. Be sure to guide them away from the fan when you replace the HU in the dash.