Short answer: Money transfers. Keys handed over. Ownership changes. Register with LINZ. Final inspection recommended.
Your lawyer transfers the purchase money to the seller lawyer. The seller gives the keys. Ownership officially transfers. You get the keys, usually around midday. Your lawyer registers the change with Land Information New Zealand. You should do a final inspection just before settlement to check nothing has changed.
Morning: Final inspection
Mid Morning: Lawyers transfer funds
Midday: Keys released
Afternoon: Ownership registered
Evening: You move in