How do you flip the handedness of a molecule?

I need to overlap two molecules that are numbered the same but have different handedness.

Cheers,
Mike

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Dr. Michael W. Day
Director - X-ray Crystallography Lab & Molecular Observatory
California Institute of Technology
Mail Code 139-74
Pasadena, CA 91125

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Beckman Institute, Room 116
Phone: (626) 395-2734
Fax: (626) 449-4159
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