Join the Motorsport Club of Hong Kong, they organise these track days a few times a year, but as a registered club/group. They will issue you temp plates and all the logistical hoo haa. Individuals are not able to do it.
http://www.mschk.com.hk/
a word of advice though, a great club this one, a little bit on the mature side, and a pretty tight group of HK elites, if you are a bit of a Honda drift racer type, you are going to fit in about as well as oil and water, it wouldnt be pretty....
If you are into open wheelers, European classic, post war or late model exotic sports cars, you'll fit right in, and benefit by their ability to arrange the best motorsport events for "their" members.
If you want to do power slides and burnouts and stuff, there is a purpose built skid pan for doing drifting etc in Lo Kwu Tan ( Tuen Mun ). Amazing what can be found, when you have abundant space, theres even an international certified outdoor go kart track here.