You can visit Victoria Peak, Stanley Market and Ocean park in the first day in HK Island. At 8pm at night, you can see Symphony of Light show in the Harbor on the ferry.
The second day, you can see Ngong Ping 360 in the morning, and then go to visit Disneyland in the afternoon.
The fourth day, you can go to visit Temple Street Night Bazaar and Wong Tai Sin Temple as they are both in Kowloon.
The fouth day, you can have a shopping in Mongkok.

From Disneyland to Royal Plaza Hotel, you just need to ride Hong Kong MTR from Disneyland Resort Station to Prince Edward Station. It takes 18HK$ for a single ticket for an adult.
Then take the metro to Admiralty. From Exit B, you can find the bus 629 to Ocean Peak, find the bus 15 outside Admiralty Garden, you can get to Victoria Peak. You can take bus 15 from Mount Kellett Road, Peak Road to Mount Kellett Road, Peak Road. Then transfer bus 6 to Stanley Village, Stanley Village Road(HKD17.5）.
Take MTR from MTR Mong Kok Station - C1 and get off at MTR Tung Chung Station - B. You can walk to Ngong Ping 360. Then take MTR from MTR Tung Chung Station - B to MTR Disneyland Resort Station - A. You will get to Disneyland. Take MTR from MTR Disneyland Resort Station - A to MTR Mong Kok Station - C1.You will back to Mongkok.
Take bus E21A from Sai Yeung Choi Street to Man Kee Mansion, Waterloo Road. Then take bus 103 to SHELLEY STREET/Shelley Street, Caine Road. You will get to Temple Street Night Bazaar(HKD12.8). Take bus 103 from Caritas Centre, Caine Road to Chuk Yuen Estate. You will come to Wong Tai Sin Temple(HKD9.8).
Bus A21 can take you from the hotel to the airport. It costs HKD33.