If the navcore (application) on your device is currently at least version 9.01x or higher, then you can install the full featured Australia 915.5074 map.
Simple instructions are already in the first post of this thread. Just copy across the new map folder into the root of the device. Run FastActivate and patch the map.
There are a couple of old guides or tutorials:
1) To simply update the map:
2) For a full clean install, follow this tutorial:
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