Step 1 - Download the appropriate mapset installer - see the download page for more information as to which is the correct installer for your GPS unit.
Step 2 - Run the installer, follow the prompts in the installer and allow the maps to install. The installer integrates the maps into MapSource.
Step 3 - Start MapSource
Step 4 - Select the Free Open GPS NZ Maps using the product selection drop-down menu. NB if you only have one mapset, use the menu path View -> Switch to Product -> Free Open GPS NZ Autorouting
Step 5 - Click on the Map Selection tool on the toolbar
Step 6 - Use view/zoom out region or manually zoom out and draw a box around all of NZ. Make sure you have all of the maps - there are 10 map tiles including 2 Zenbu POI. Make sure the 'Include Route calculation data' checkbox is ticked.
Step 7 - Click on the Send to Device button on the toolbar
Step 8 - Select your GPS device from the list, make sure the Maps is ticked in the 'What to send' section, and click 'Send'
Step 9 - MapSource will build the MapSet and then send to your GPS. Usually this will take a minute or two.