Delete the VST from here:
MAC HD > LIBRARY > AUDIO > PLUG-INS > VST
Delete the AU from here:
MAC HD > LIBRARY > AUDIO > PLUG-INS > COMPONENTS
Close all applications and delete the 'com.vsoft.novation.vstationV1.plist' from USERS > "YOUR NAME" > LIBRARY > PREFERENCES.
Once you have deleted these files, run the latest V-Station installer (http://www.novationmusic.com/support/v_station/), restart your Mac and boot up Logic.