Use Compustat. Faculty, PhD students and full-time MBA students are eligible for their own accounts; all others should come to Pius Library and use Compustat on Terminal A or B.
Select "Index Constituents" from the menu on the left.
Choose the date range.
Choose "search entire database."
Select the Index and Company information you want to see displayed (at minimum, Index Name & Ticker and Company Name & Ticker).
Choose the format (such as xls) in which you want to view the results, then click Submit Query.