regarding visit visa for a day

Hi,
I hold Nepalese Passport and I am a permanent resident of Australia.I am travelling to Sydney from Nepal on 22/07/2018 and I have about16 hours transit in Hong Kong airport from about 6am to 9 pm.So, I am planning to go to Disney land and some other tourist spots close to airport during my transit.I would like to know how I can apply for one day visitor visa for Hong Kong.I live in Sydney.