Just google the info for yourself. Unless Australia comes to the aid of the Kiwis, it would be a like stealing candy from a baby.
http://en.wikipedia.org/wiki/Royal_New_Zealand_Air_Force#Current_strength
http://en.wikipedia.org/wiki/Royal_New_Zealand_Navy
http://en.wikipedia.org/wiki/New_Zealand_Army
The army has 7000 personnel. Probably more than 50% are Maori who could easily be bought over is the price was right.
Only 4500 are regulars. The rest are reserves/civilians.
While Sinkies would lose in one-on-one hand to hand combat with NZ forces, [their rugby team can chalk up 3 figure scores in 10 minutes of play against Singapore] the technology and number superiority would easily overcome this inherent genetic disadvantage.
Alamak like that our armor or artillery units there can take over easily liaoz. Huat Ah. Sam then you become sinkie again liao. Wahahahahahaha!