wordprocessingdocument.open save file
//If you use a MemoryStream you can save the changes to a new file like this:
byte[] byteArray = File.ReadAllBytes("c:\\data\\hello.docx");
using (MemoryStream stream = new MemoryStream())
{
stream.Write(byteArray, 0, (int)byteArray.Length);
using (WordprocessingDocument wordDoc = WordprocessingDocument.Open(stream, true))
{
// Do work here
}
// Save the file with the new name
File.WriteAllBytes("C:\\data\\newFileName.docx", stream.ToArray());
}