If you have a split phase motor (with two windings) and all four leads are accesible, then you can reverse its direction by reversing the ends of one of the winding. If a capacitor and centrifugal switch is involved its treated as part of the aux. winding.
Suggestion: Some caution must be exercised, since not all motors are built to work in both directions of rotation. Check the fan cooling, and look for any arrow on the motor body and CW or CCW on the nameplate or within the documentation.
