Walk all the way down Tonsai Beach toward the Firewall (where the long tail boats parked, the opposite direction of Tonsai Roof).  Take a right on the cement road and continue approximately 100 meters until you see a (very) faint trail with a fixed rope that will take you toward the wall via a 3rd class scramble. 

To get to the main ledge, you will need to put your harness on and continue climbing another fixed rope.  Use caution.