I have a 2005 350z that came stock with a basic single disk cd changer. I have a Bose 6 disk cd changer and a Bose subwoofer with amp that came from a 2004 350z. What else do I need to do the swap from single disk to the cd changer into my Z.

 

you can download the fsm from my Link Page and see for yourself what's all involved.
There's a complete breakdown of the whole AV system in the fsm.