1. The Best Way is via MTR:
At Tsim Sha Tsui MTR Station just across the street from Sheraton, take the "HK Island Line" bound for "Sheung Wan" and get off at "Central" Station. Landmark is minutes' walk.

2. If you have more time, take Star Ferry to enjoy the view.
Tsim Sha Tsui Ferry Terminal is about 5 minutes walk from the Cultural Center.
If you get off at the Central Ferry Terminal, Landmark is a bit far away, but you can walk if you have some spare time to enjoy walking on the streets.

3. By taxi, it costs about HK$100.00 including the tunnel charge.
(In this case, be sure to tell the driver to take the Cross-Harbour Tunnel as opposed to the Western Harbour Crossing tunnel, which is faster to get to HK Island but way more expensive, sometimes costing more than HK$170, hence good for the driver, a disaster for the passengers)