C#

private void button1_Click(object sender, EventArgs e)
{
    if (openFileDialog1.FileName.Length > 0)
        {
            string path = openFileDialog1.FileName; // The Path to the .Xml file //
            FileStream READER = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite); //Set up the filestream (READER) //
            System.Xml.XmlDocument CharDetail = new System.Xml.XmlDocument();// Set up the XmlDocument (CharDetail) //
            CharDetail.Load(READER); //Load the data from the file into the XmlDocument (CharDetail) //

            System.Xml.XmlNodeList NodeList = CharDetail.GetElementsByTagName("Character");

            NodeList[0].FirstChild.ChildNodes[0].InnerText = CharName.Text;
            NodeList[0].FirstChild.ChildNodes[1].InnerText = Virtue.Text;
            NodeList[0].FirstChild.ChildNodes[2].InnerText = Vice.Text;

            //Save the xml file
            //Create a FileStream for writing
            FileStream WRITER = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.ReadWrite); //Set up the filestream (READER) //
            //Write the data to the filestream
            CharDetail.Save(WRITER);
        }

}