American converting X (study) to Z visa in Hong Kong (going to HK really soon!)

I am currently a student in China and I found an employer who obtained all of the paperwork for me to take to Hong Kong to apply for the Z there. They gave me all of the required paperwork except for the application. I am married to an american and we have our proof of kinship document and it was approved by the chinese consulate in the US. Not sure if there are different types of application forms ... which ones will we need? Do I need to fill out application for the two of us before we go, or is this something I have to do when I get to Hong Kong? Anyone with experience going to HK please advise???