How to replace the nodes based on attribute using xslt

Below is the input xml: Below xml contains cases which is have individual transactions, these transactions need to be replaced with newNode transactions based on attribute of id(id generated unique)

 <?xml version="1.0" encoding="UTF-8"?>
    <DST>
      <CDGCreateTree>
        <DST>
          <currentJobName>PQContactComplete</currentJobName>
          <AWD>
            <case>
               <transaction relate="Y" id="6745635345346567567567-T01"/>   
            </case>
            <case>
              <transaction>
                <UIID>Test</UIID>
              </transaction>
            </case>
           </AWD>
        </DST>
      </CDGCreateTree> 
       <newNode>
        <transaction relate="Y" id="456567535646674524345-TSY"/>   
      </newNode>
    </DST>

   My requirement is like second case transaction need to be replaced with newNode transaction by           the checking condition like (//transaction[ancestor::*[name() = "CDGCreateTree"]][not(@id)])[1].

   Expected Result: 

    <?xml version="1.0" encoding="UTF-8"?>
    <DST>
      <CDGCreateTree>
        <DST>
          <currentJobName>PQContactComplete</currentJobName>
          <AWD>
            <case>
               <transaction relate="Y" id="6745635345346567567567-T01"/>   
            </case>
            <case>
              <transaction relate="Y" id="456567535646674524345-TSY"/>   
            </case>
           </AWD>
        </DST>
      </CDGCreateTree> 

    </DST>

I have tried below XSLT, But it is not helped me, Please any one suggest me on this.

     <?xml version="1.0"?>
    <xsl:stylesheet xmlns:xsl="http://ift.tt/tCZ8VR" version = "1.0">

    <xsl:template match="@* | node()">
        <xsl:copy>
            <xsl:apply-templates select="@* | node()" />
        </xsl:copy>         
    </xsl:template>

    <xsl:variable name="targetNode" select="//newNode/transaction"/>

    <xsl:template match="(//transaction[ancestor::*[name() = "CDGCreateTree"]][not(@id)])[1]">
       <xsl:copy-of select="$targetNode"/>
    </xsl:template>
    </xsl:stylesheet>