You will need to complete an application to change RUC vehicle type (RUCCV) through NZTA. You can contact them on 0800 655 644 for more information or visit their website.
Once this has been done you can change the RUC vehicle type through the following steps:
Open up RUC Manager, under the Vehicles tab
Select the vehicle you are wanting to change
Select 'Edit' under the Vehicle Defaults box
Using the drop down next to 'Default Licence Type', select the new licence type
You can find instructions on how to purchase an overlap licence, if required, under Purchasing RUC licences.
RUC Manager is permission specific, please contact your admin user or Coretex Support if you do not have access to this.