This has probably been covered a bunch of times, but I couldn't find my answer searching this forum or the entire forum. How the hell do you remove the stock Kenwood HU? I put the tools in, I started pulling, and it stopped after coming out about 2 inches. Is the security screw in the back done at the factory? If so, how the hell do you get behind to take it off? Links to instructions or pictures would be helpful as well.