People surrender weapons to the NZ police all the time. There is an official process via which you can do this.
One common reason to do so is where the license holder dies, or no longer is active (e.g. age)
These kind of weapons cannot be passed to someone else unless they hold the required license and have the security storage required by the police and it has been vetted.
So either you sell the gun through a dealer, or more likely get rid of it.
Ok thank you, it sounded as though she was asking people who currently own guns and are active with them to turn them in because of impending changes to the gun laws. That still isn't clear to me.