2 Word Documents 2 Separate EndNote Libraries - How to Merge?

Hi, I have 2 Word documents which are associated with 2 separate EndNote Libraries. Now I need to merge the Word documents. How can I format correctly the bibliographies in the merged document with the 2 EndNote libraries? I read about formatting a Word document first and then delinking and then copying and pasting. Is there a quick and easy fix for that? If I merge the EndNote libraries, the newly added references are assigned new record numbers. Thus, the bibliographies in one of the Word documents will have problems. Thanks a lot!