Berealgetreal under the Trans-Tasman Mutual Recognition Act (TTMRA) the Australian and Kiwi licence can be converted by a paper trail. Google TTMRA.
There are a few little 'problems', the Kiwis do not recognize Co-Pilot endorsements.
The Kiwi Command Instrument Rating can only be bounced back for an Aussie one once.
They will only endorse aircraft on the Kiwi register.
The Kiwis have a fixation about 'mountain flying' in the questionnaire. Best not to say you've flown over a couple, they mean something else apparently.
Compared to CASA, CAA are easy to deal with, lovely people.
The forms are the usual crap about being 'a fit and proper person' and all the twaddle about witness suitability. My Chinese Chemist was 'suitable' but all my Airline Captain friends were most certainly not. (wise people somewhere in those halls of officialdom).