How to remove whole Xmlnode so that outer tags are also removed ?

To reproduce, run the code.

Observed result:

<Query>
 <DataSourceName>DS1</DataSourceName>
   <QueryParameters>
   </QueryParameters>
 </Query>

Expected result:

<Query>
 <DataSourceName>DS1</DataSourceName>
 </Query>

How to get expected result ?

I tried

qp.OuterXml = "";

but got error

Property or indexer 'System.Xml.XmlNode.OuterXml' cannot be assigned
to -- it is read only

Code to reproduce:

using System;
using System.IO;
using System.Xml;
class test {

public static void Main() {

 XmlDocument xmlDocument = new XmlDocument();
 XmlNamespaceManager nsmgr = new
XmlNamespaceManager(xmlDocument.NameTable);
 nsmgr.AddNamespace("def",
   "http://schemas.microsoft.com/sqlserver/reporting/2005/01/reportdefinition");

 xmlDocument.LoadXml(@"<?xml version=""1.0"" encoding=""utf-8""?>
<Report
xmlns=""http://schemas.microsoft.com/sqlserver/reporting/2005/01/reportdefinition""
xmlns:rd=""http://schemas.microsoft.com/SQLServer/reporting/reportdesigner"">
 <DataSources>
   <DataSource Name=""DS1"">
   </DataSource>
 </DataSources>
 <DataSets>
   <DataSet Name=""Data"">
     <Query>
       <DataSourceName>DS1</DataSourceName>
       <QueryParameters>
         <QueryParameter Name=""p0"">
           <Value>16.06.1998 0:00:00</Value>
         </QueryParameter>
         <QueryParameter Name=""p1"">
           <Value>16.06.1999 0:00:00</Value>
         </QueryParameter>
       </QueryParameters>
     </Query>
   </DataSet>
 </DataSets>
</Report>");

 XmlNode qp = xmlDocument.SelectSingleNode(
           "//def:QueryParameters", nsmgr);

// Property or indexer 'System.Xml.XmlNode.OuterXml' cannot be assigned
// to -- it is read only:
// qp.OuterXml = "";

// this does not reove whole node !
 qp.RemoveAll();
 xmlDocument.Save(Console.Out);
}
}

Andrus.