If your working with a Honda and your a big guy... see if you can pursuade a small friend to help out. I'm only a little over 6' but couldn't quite reach some of the spaces that needed to be reached.

Seriously though, once you have the wiring all done... it took us about 1.3 hours for my first one. That included us making a custom bracket (bent metal with 2 screw holes) to hold up the rear end of the HU.