The following code will give you the coordinates of the cache:
This took my computer about 1 millisecond to compile and run. I supose you could work this out manually with pen and paper, but I probably wouldn't recommend doing it (the code performs almost 4000 iterations of the loops).
The cache is a small bucket with room enough for a fair bit of swaps and TB's. I provided pens but don't trust them, bring your own just in case. Please cover up when finished. FTF prize is a 1 month premium membership. If you already have a premium membership, why not give it to a friend to help promote Geocaching.
If you have a 2WD, access is fine from the Kangy-angy side, if you have a 4WD or at least something with a bit of clearance, the way in from the tuggerah side would be OK.
On your way in, check out the iron cross (grave?) at the listed coordinates. If anyone knows the story about why this is here, I would be interested to know.
Access to the fire trail is to the left of the iron cross. This is not private property, although if you venture too far down the road you will find some.
Enjoy!!
You can check your answers for this puzzle on GeoChecker.com.