Information is power, and the info you need is in the public library in Chilton's Auto Repair manual. You will kick yourself after you see how not complicated this is. You can buy your own manual at Autozone or Kragens. Once you pull off the trim in front of the radio, 4 screws hold it in. Be careful with the plugs so you know where to put them back right. You might want the color code unless you bought a radio adapting harness. Try this:
http://www.the12volt.com/installbay/...rd/Toyota.html