All they really need to do is simply get a very long stick and keep pushing it away in the direction THEY want it to go.
I've got a fully grown Sand Goanna that wandered into my front yard years ago during a very dry spell, she has a damaged hind foot and was visibly starving and thirsty so I fed her.
She, Anna the Goanna, has lived here ever since eating snails, mice and other vermin, roams about at her leisure and she will sit beside my Nephew Henry ( 5 years of age) on the lawn and be patted by him for hours.
Goannas do NOT deliberately ATTACK people, their instinct when feeling cornered or threatened is to climb the highest looking thing in their vicinity using the very long and sharp claws on their 'feet' to grip as they climb, that rank idiot needs, in my honest and well educated bushman's opinion, to learn more about the Aussie bush and the animals living in it.
Goannas are the nemesis of snakes, they prey upon them and where you see a goanna you most likely won't see a snake for miles around.