Every program I open up the files in just shows a bunch of code. Open XML SDK: Open XML is a lower level API to build the Word document VSTO (Visual Studio Tools for Office) : .dll from VSTO provides APIs to directly automate Word application itself to build a document. For implementing this, you should use the classes in the Open XML SDK 2.0 for Microsoft Office to programmatically search and replace a text value in a word processing document. About this situation, you could refer to the following links for further information about MainDocumentPart and Search and Replace Text in a Document Part.Open an XML File To open an XML file, you can drag and drop it in a new tab of your browser, then it will be opened by the browser. To convert XML to Word with PDFelement, you need to take the 3 steps summarized as follows: Step 1.