Walmart has the plug in wire harness for the KJ, and the trim piece (installation kit). Just take the plug from the head unit, and splice the wire to the after market plug. Then pull your stock unit out unhook the plug. Hook up the after market harness to the stock plug and your good to go
To get the center piece off there's one screw by the power port you take that out, and then take a thin blade screw drive and pop the trim piece off
It took me about 20mins to put my Pioneer in
Edit: Here a link to the wire harness I'm talking about
http://www.crutchfield.com/S-CAVfUZlnBt ... =120706502