Merge and remove duplicates within multiple XML files

Question

I have business users that receive multiple XML files that they are importing into excel so they can merge the data and remove duplicates. They have to do this multiple times a day and it is quite time consuming.

Is there an easy way to merge XML files and remove duplicates? I have seen multiple examples but am not sure how to achieve the following:

1. Users have a static directory where they could place the XML files
2. Within that directory they could open an index.html page which would execute the XML merge code.
3. Merge and remove duplicates
4. Render the results as HTML.

Assumptions: The files will conform to a naming convention (File1.xml, File2.xml, File3.xml and so on) The XML files will always be of the same schema