MTR:
Ride the MTR to North Point or Quarry Bay, then change the Island line towards
Sheung Wan. Get off the MTR in Central. Then walk to the Hong Kong Station
which it is also in Central Station( will have notices for u) and change the Airport Express Line. Get of The MTR in The last STATION --Asia World Expo
Cost: 100 or more (But will have discount on that day, check in the MTR Official Web)