You mean ANZ…As long as your APIM will have enough storage, you can. However, this is technically changing regions, and CyanLabs does not support that.
You can use the updater to load the new version and ROW maps and voice. You will need to change the region info in the APIM.
A good tutorial to read is Archive: EU Maps to US Car (3.4 Sync, F9 Maps), although not exactly what you want to do, it has the steps you should follow.