from the article.....
There is a considerable debate about how they should be managed, in particular, conservation groups believe their environmental impact outweighs their social value, although this is contested by hunting organisations who aim to preserve deer populations for future generations. Sambar deer are currently listed as protected wildlife game species in Victoria and New South Wales, and a game licence is required to hunt them. They are declared pest species in in all other Australian states and territories and can be hunted at any time with no bag limits. Environmental and conservation groups want them declared a feral species in all states, due to their exploding populations and negative impact on biodiversity and native species.
I think that the only way is to shoot them...perhaps let friends know you want them gone, for free. This assumes you are in one of the areas where they are unprotected from any hunting restrictions. Any chance you can headlight them at night?