Hi all, from my research it looks like I will need to get my qualification assessed by NZQA. What is the process to do this?

I have a National Diploma: Electrical Engineering: Digital Technology from Tshwane University of Technology in South Africa (obtained in 2008) and 9 years of experience as an Electronic Design Engineer.
On immigration.govt.nz it states that qualifications can be substituted with experience, how does this work? Is it only for the visa process or does it apply to NZQA as well?