How can I open an XML File and replace an attribute value?

[codeguy03]

Lets say my value looks like this in the xml file


<<PARTNUMBER Value="352698563 " />


How can I replace that value number?

So far I have this

XmlDocument doc = new XmlDocument();
XmlNode node;


doc.Load(filename);

xpath = string.Format(@".//{0}[@{1}]", "PARTNUMBER" , "Value");
node = doc.DocumentElement.SelectSingleNode(xpath);


it successfully navigates to that node but how do I replace the value?