i presume you mean the wiring? ill assume you got and can use a multimeter
what ya do is get your multimeter out and where the old hu plugs in put the red probe on a random wire try yellow if there isnt a yellow just alternate between all the wires with the ignition turned to acc (the black probe is on the vehicles chasis) when you get 12v thats your acc, then turn the ignition on and repeat the above process till you get 12v again, for the ground from the hu wrap it around a screw from the mounting bracket and thats all of it. apart from the speakers and you should probably rewire em as theyll more than likely have a common earth which im told kills the hu