I'm sorry to tell you, but the cost to retrofit a Nismo bodykit is generally more expensive than the cost difference of buying a Nismo in the first place. But you can do pretty much whatever you want depending on your wallet. First, you need to figure out which Nismo bodykit you want (2009? 2013? 2015?). Then you need to search for what parts you need (note you might need some additional misc OEM parts for proper fitment). Then you have to source all the parts. Then you have to find a competent shop to do the work.
The forum search function is pretty crappy except for advanced searching. Try using your favorite search engine and add
site:the370z.com to your search string
