How to Save As a .DOC File
Various versions of Word differ in how to save as the old format .DOC file format, but it should be something like this:
Click on "File"
Click "Save As"
Choose the file format to save as that says something like "Word 97-2003 Document"
Save it to whatever name you like, say ConvertMe.doc
That's it, now you can upload it to see how it gets converted.