There's a form you and your parents need to fill in to determine what your parent's financial income and assets are and whether you are getting paid the fair amount.
You only need to have your parents fill out the form if you're living at home or otherwise classified as being dependent on them. So if you're living by yourself or are independent, then you need to contact Centrelink and tell them that you don't need to fill out the form.
Otherwise, you need to obtain the Family Actual Means Test form and submit it as soon as possible. Simple as that.
The questions are all concerned with how much your parents earn, what financial assets they have and what their expenses are.