I'm Pakistani passport and I am living in China from more than 4 years , I have z Visa, how can I get a visa to Hong Kong?

Dear Sir i have pakistani passport and i am living in china from more then 4 years , i have z Visa, i want to travel to honkong just for holidays not for work so which things i need to give and also what else i have do to get hong kong visa i have office in yiwu zhejiang and also in shenzhen but my company resgistered in yiwu . so kindly tell he how to apply and which documents need so i can apply for that in shenzhen .
Thanks