I've recently moved over to 2degrees and want to get Wifi Calling setup on my Vodafone purchased Galaxy Note 8 (SM-N950F).

The 2Degrees site states " If you purchased your Samsung Galaxy phone from another mobile provider in NZ, it will need a software upgrade. Simply bring your phone into any 2degrees store and we’ll help sort this out for you. "  Is this software update available anywhere publicly so I can do this myself or do I actually have to go in store for this?

https://www.2degreesmobile.co.nz/help-and-support/mobile/products-and-services/wifi-calling/  

I initially tried flashing the firmware & CSC with odin but Samsung stopped this from working with Oreo.