In the General Reference and Periodicals Department of the University of Miami, the Abstracts and Index collection had traditionally been arranged alphabetically by title. In 1985 and 1986, all of these serials were cataloged. In June of 1986, with the cataloging finished, it was time to rearrange the collection into call number order. The authors developed a methodology which allowed them to drastically disrupt and rearrange a highly used collection while maintaining high standards of service and accessibility. A collection of over 7,000 volumes was shifted in less than four days with very little manpower and no interruption in reference service. This article takes the reader step-by-step through this methodology