First you have to go to Dadar (western) (not to be confused with Dadar Central or Dadar Terminus - although all are linked by FOB). Then take a slow train to Bandra which halts at Matunga Road and Mahim (Fast is also possible but may be crowded). You will disembark on platform #1 which is on the west side of the railwayline. You have to used the FOB and get down on the east side. Then Bandra Terminus is a few minutes away by Auto