Assuming the NZ system is similar to UK system, the CAA are no longer issueing LWTR you will now have to go for JAA 66 B1, and that will take a lot of conversion, whereas before you would of only had to do air leg, i's a bit more involved. Have a look at the CAA website
CAA and go to the Safety regulation pages all the info should be there. Good luck I think you might need it.