It's really easy..have a look in the owner's manual under DIY and maintainance. It only takes 5 mins to do both of them, no bumper off needed..and that's coming from someone who is non-technical like myself
I am with Rich on this one..it takes a lot of effort and time to come up with comprehensive guides and the man should be applauded for his effort regardless of how easy it is. Just like AlexZ's.
+1 Not sure about the number plate being at the sides alfa romeo stylee I have remounted mine on the tow eye using one of these mounting brackets http://www.350z-uk.com/forum/viewtopic.php?f=33&t=33320 or go for something like these http://www.350z-uk.com/forum/viewtopic.php?f=33&t=32587