Take a taxi from the airport to the OUE Bayfront Building (located at number 50, Collyer Quay). Ask the taxi driver to drop you at the taxi drop off point in front of the OUE Bayfront Building (on Collyer Quay Road). This is currently located just before the B02 bus stop (and immediately after the overhead walkway).
By MRT (tube):
Take the MRT to Raffles place. Walk through Change Alley until you reach the road (near the Hitachi Tower taxi stand), take the escalator up one level and walk across the overhead walkway bridge. Take one level back down (to street level), turn right and enter the OUE Bayfront Building. We are located on level 9.