You need each and every single .NCA file, preferably in their own folder on the root of the SD card. For extracting them, hactool is the best one to extract it in my opinion but I usually just use xbins to obtain the firmware files rather than going through the trouble of extracting them from an .XCI file.
Awesome, thanks very much. I'll try using hactool first.
Just curious, but when you're referring to "xbins" do you mean the page with all the file listings, or their FTP servers, which I just discovered are a thing. That might explain why I'm not finding the stuff people say I can just get off xbins >_>