Overseas voters can download their voting papers from the Electoral Commission website and return their votes by uploading their voting papers again at the Electoral Commission's website.
New Zealand, Electoral Commission Website, Vote from overseas, accessed 19 October 2020
“When you’ve marked your voting papers, return them to us in one of the following ways:
Upload them online
Fax them back to us: Fax: +64 4 494 2300
Post or hand deliver them to your nearest overseas voting place
You cannot return your voting papers by email.
Your voting papers will include full information on how to return them.”