It'll work like this ( I went through this twice):
1. Take the Trial option and Check "Not Guilty" Box
2. Send the form back or go to the court (centrepoint, Nepean City Hall) and file a case
3. You'll receive a mail late on indicating the trial date (usually after a couple of months)
4. Go to court on trial day, should be there as early as possible;
5. Look and ask arround in the court room to see if the cop who charged you is there:
6a. if the cop isn't there, relax, go to the procecution officer sitting in the front row, register your case and insiste "not guilty"
7a. The judge will come in and go through the case one by one; When it's your turn, explain that you don't agree with the officer because of ..... try not to lie, like "I didn't exceed the speed limit ..." instead, you can say " the office didn't show me the meter reading", "I don't think I was speeding at that time" "He must spotted another car in front of me"...
8a. most likly, you case will be dismissed immiately
6b. If the officer is there, say hello to him, and explain that the reason why you come here and take the trial is to see if they can reduce the fine and points ... Do be very nice and friendly with him/her, no argument at all !!!
7b. go to see and register (BEFORE the judge come in!!!) with the procecution office and explain that you'll plea guilty (in sead of "not guilty" on your form) as you've chatted with he police officer and see if the fine and points could be reduced. Usually, the procecution officer will either reduce the fine or the points or both;
8b. Judge comes in and you just plea guilty and the judge will make a decision based on the material provided by the procecution officer
If you're there too late and miss the chance to talk to the procecution officer, what could happen is that the Judge will make an adjourn after the first a couple of cases and tell people "you might want to talk to the procecution office ..." and the procecution officer will go to another room and meeting people one by one, that's your second chance to explain to reduce the fine and points!
BTW, the chance of "no shown" by the cop is very slim these days, they'll make every effort possible to be there, as they'll be fined otherwise.