The Technosquare website has pictoral instructions for how to remove the ECU from a 350Z. I found it quite helpful and nearly identical in procedure to remove the ECU out of my FX45 when I got it reflashed. Different animals but nearly identical procedures...I'm sure the 370Z will be very similar too. Here's the link from their website:
<TECHNOSQUARE - PRODUCTS - TECHNOSQUARE - TECHNOS 350Z ECU FAQ>