That's because most people never take off the dash, and when they do, they don't post a DIY!!
It is actually really hard and complicated to get it off.... and the only reason I was able to was because I had a new one to install (from a Prizm). So, I can show you the bolts and stuff to take off, but good luck doing it! You're going to need it lol.
Taken from my page (
http://www.cardomain.com/ride/801395/7#PrizmDash)
"(this is the new Prizm dash). So, I figured out how to remove the dash. This pic was taken later for reference. It is pretty easy to get the dashboard disconnected from the car, so that the wires are the only thing holding it in. To get to the wires, you need to remove the defroster vent by unscrewing the 6 screws circled in red."
"Once that is pulled out of the way, you can remove all of the screws holding in the wires (circled in red again). When removing the dash from in the car, I had no idea what I was doing; I had to feel around and pull on stuff to figure out where the screws were, and then get the screwdriver up back there to unscrew them. Hopefully this helps you some, but it is hard to explain XD"
"But eventually, I got it out. I ended up breaking the dash and duct a bunch... but they were worthless anyway. You should remove the steering wheel column to get it out. There are 4 large bronze bolts under it, so remove those and the wheel comes down."
So you can see how much work it is. You have to do all of this while it is installed, and the screws all face towards the windshield. Give it a try and let me know if you have any more q's!!!