Hey anskuhh let me be the first to congratulate you my friend! It seems your process is coming to an end.
What they want from you is a New Zealand police certificate. I believe they are asking for one because the one you sent them in the beginning has expired and they want a new one. (that's in case you became a mass murdered during these months hehe

)
So check this out and run fast. You must send this one in no later by the date mentioned. Here is the info how to obtain one:
http://www.cic.gc.ca/english/information/security/police-cert/asia-pacific/new-zealand.asp
Also in this email they are actually informing you that your interview has been waived you lucky dog ;D
you do not need to send a passport. Don't get confused! Just stick to what they are asking you. If you are from NZ then you are from a Visa exempt country so there is no need to stamp your passport!
Now. Once you have the Police certificate in your hands go to this site which is the Sydney Case Specific:
https://dmp-portal.cic.gc.ca/enquiries-renseignements/case-cas-eng.aspx?mission=sydney and follow the instructions and send them a message and ask them where to send the Police Certificate because I believe that you have to send the original document. But if you can send a scan then you may send it through this site along with your message as an attachment.
Or you may join the Sydney thread here in the forum and some more experienced members can guide you where to send it.
I am surprised they did not inform you where to send it in this email.
If you do the above you are A1 ok
One last word. Although we at some other VO's seem to have a long wait I must tell you that I am very very happy for you. Nothing was moving this summer and these are great news.
All the best
Keep in touch so we know how you're doing
Tom