A family of Microsoft word processing software products for creating web, email, and print documents.
One the Mailings tab of the ribbon, expand the Start Mail Merge dropdown in the Start Mail Merge section of the ribbon and then select Normal Word Document and save the document. That will remove the data source from the document. If desired, before saving, select the type of mail merge main document that it was and then save the document. It will then be saved as a mail merge main document, but without a data source attached to it.