Where's Mount Stong? Do you mean Mount Kinabalu, situated in Kundasang, Sabah?
Anyway, I've hiked that mountain before and no, you don't just barge in and say, "Hi, may I hike the mountain right now?" You need to make reservations AT LEAST half a year before to book for places at the small chalets up on the mountain to sleep over night. Lots of other things to do as well. For more information, you can always search the website of the mountain you are hiking and get more info on what you have to do.
Hope this helps!