The instruction manual was written for the DIY person. That said, there is a certain amount of common sense that is needed to do the installation. There are times, when you'll really need to stop and think about what you are doing and make sure that you understand what you are doing and why. Knowing how the components interact together is a really big help when doing a DIY install on something like a Twin Turbo kit. I mean, if you don't know how a wastegate works, look it up and learn it. Same goes for the blow off valve. That way, when you're in there routing hoses, you know why we're saying to route them a certain way.
Granted, you can do the install and really not know what it is that you're actually doing and get away with it, but if you put a hose on the wrong nipple and on your first test drive, your car isn't boosting or overboosting, you'll be up the proverbial creek without a paddle because you won't be able to troubleshoot the issue.
Also, keep in mind that the 370Z has a really, really tight engine bay. You are going to be stuffing two turbos and a lot of piping in there. You're going to need some dexterity and special tools to be able to tighten some of the bolts, because they're a real PITA to get to. It's just the nature of the beast.
Here is the link to the 370Z instruction manual:
http://www.gtmotorsports.com/Manuals...structions.pdf