Code Maintenance

I have an application that deserializes an XML file.

I generated a class from an XSD with XSD.EXE

For deserialization I use the following code:

static T LoadFromXMLString<T>(string xmlText)
{
    var stringReader = new System.IO.StringReader(xmlText);
    var serializer = new XmlSerializer(typeof(T));
    return (T)serializer.Deserialize(stringReader);
}

I call it as follows:

var _ProcNFe = LoadFromXMLString<ProcNFe.TNfeProc>(XmlProcNFe);

After that, I use the _ProcNFe object to write some fields to the database.

However, a doubt has arisen, the XSD I originally used will be changed and consequently the generated class as well.

What would be correct, create a new class from this new version of XSD or change the existing one to conform to the new XSD?