The fastest way is to take airport express train from HK airport to Hong Kong/Central Station. Then walk to the Peak Tram in Garden Road or take bus 15 at Central Pier bus terminus, near Central Pier 5. After that, the same way back to Central. Then take Tung Chung MTR Line to Sunny Bay where you can change to Disney rsort line to Disneyland. When you get back to airport, you can take mtr to Tung Chung Station and then change to bus S1 to the airport. This is the cheapest way. If not, you can take a taxi. It costs about 100-110HKD from Disneyland to the airprort.