Mr.neeraj,
No.1 Butterfly Beach: take Tsuen Wan Line to Tsuen Wan MTR Station. Then go Tsuen Wan Bus Station to take 59M to Butterfuly Beach. Or you can go to Mong Kok Train Station or Prince Edward MTR Station to take 59X to Buterfly Beach.

No.2 Golden Beach: take Tsuen Wan Line to Mei Foo and then change 52X bus.

No.3 Big Wave Beach: go to Shau Kei Wan and take No.9 bus.
No.4 Shek O Beach: take No.9 bus from Shau Kei Wan.
Repulse Beach: Exit D at Hong Kong MTR Station and walk to Exchange Square and take 6, 6A, 6X, 66 or 260 and get off at Repulse Bay.

No.5 Deep Water Bay Beach: take 6A,6X bus at Exchange Square in Central and get off at Deep Water Bay.

No.6 Hung Shing Yeh Beach: take ferry at Central Pier 4 to Lamma Island and walk along Family Trail for 20 minutes.

No.7 Cheung Chau Tung Wan Beach: take ferry at Central Pier 2 to Park Island and then walk 8 to 10 minutes. Or go to Tsuen Wan West MTR Station and take ferry to Park Islan and walk 8 to 10 minutes.

No.8 Pui O Beach: take ferry at Central Pier 6 to Mui Wo and take No.1 or No.4 bus from the ferry terminal to Pui O. Then walk around 10 minutes.

Cheung Sha Beach: From Central Hong Kong by Ferry, take Ferry Pier Number 5 to Mui Wo (fast ot slow ferry available). Then, in Mui Wo take a bus to Cheung Sha beach (lower). Take Bus number 1, 2, 3 or 4. It takes roughly 20 min to get there.

No.9 Palm Beach: first take Tsuen Wan Line to Lai King and change Tung Chung Line to Tung Chung MTR Station. Then take No. 11, 23, A35 bus from Tung Chung Bus Staion and get off at Butterfly Rest Bus Stop.