There is a guide:
http://www.350z-uk.com/topic/65948-grounding-kit-guide/page__fromsearch__1
Look thru it... You will need 5 wires, sizes are in the guide, + 10 connectors and 10 heat shrink end to put on connectors/end of wire!
And follow the guide(I think it's for LHD cars, so might need to reverse few things...can't remember, done mine last year)
So the hardest bit of it is... to find bloody wire with currectl size/color