Available via Contrail right now is the first major update to NZAA (MSFS) which includes the newly-developed custom VDGS systems present in both the International and Domestic terminals.
The update will automatically install the VDGS module, so you're set to explore them right away without extra work.
There is also no need to do anything special to activate the devices. Simply taxi towards a gate and it will automatically detect your current position and aircraft type. Approach carefully and precision guidance will begin!
Tip: Taxi speed for precision guidance is quite slow, we recommend something close to a brisk walking speed as you approach the stop markers. As a general guideline in real aviation, you are going too fast if you see all your ground crew running away from your gate.
A final note: VDGS is still optional. If you wish to disable the module, simply open Contrail, select NZAA and click the Configuration tab, then uninstall the VDGS module.
Happy flying! (and taxiing)