I have some code to replace text inside a word 2010 docx.
object fileName = Path.Combine(System.Windows.Forms.Application.StartupPath, \"document.doc
You can try this :
var doc = new Microsoft.Office.Interop.Word.Application().Documents.Open("document.docx"); doc.Content.Find.Execute( "{id}", false, true, false, false, false, true, 1, false, "12345", 2, false, false, false, false); doc.Save();