1. Open the main document to remove the data source
2. On the Tools menu, click Mail Merge
3. Under Main document, click Create, and then click Restore to Normal Word Document. Note: Merge fields and other text will remain in the document after restoring to a normal word document.
4. Select Tools, Mail Merge, and click Open Data Source. Browse for the data file. Select the Merge step, and click the Merge button.