Id say a 5 on the HRC kit...it wasnt that hard at all. Unless you dont know how to use a drill and lose all the bolts when you take them off your ride...its easy. The hardest part is drilling the oil pan and the drilling part is easy. Its just a pain to get that thing off. Everything else is pretty simple. You could do it without instructions if you knew what had to be done. But like myself on my first turbo install I had no clue so read the instructions a couple times and once more, it will be easy if you do. Good Luck...!~