installation of a head unit is very easy... usually the wires are even labeled, and at very least they are color coded and the colors can be easily looked up online, so dont let the amount of wires intimidate you
are you trying to replace the stock head unit, or the cd changer? it almost sounds like you are trying to put the clarion unit in the cd changers spot, which i can imagine would cause problems with wiring becuase the cd changer only inputs into the factory head unit