DocuWare provides 2 tools for changing many index entries. Either AutoIndex or the Index Cleaner App as indicated by Gerardo. Workflows, Manual selection and SDK options are not required and introduce more work than required.
Footnote. As indicated by Josef, once you get a result list, click on the result list context menu (3 vertical dots), and select Change Index entries for all documents. That will also process the entire Result list up to 10,000 documents at a time.
Phil Robson
Senior Director Support Americas