how do i get rambler garden hotel from the hkia at 11pm?

You can take bus no.A31 at Airport (GTC) Bus Terminus, get off at Ching Tao House Cheung Ching Estate. Then walk southeast around 250 yards (230 meters) to find the hotel. The last schedules of this bus is at the midnight.

If you cannot catch it, take bus no.N31 to get to Cheung On Bus Terminus. Then transfer to bus no.N241 to Ching Tao House Cheung Ching Estate. It takes around 85 mins on the way. The ticket fare is 30.7 HKD per person. After that, walk southeast around 250 yards (230 meters).