Steps

      <xsl:stylesheet
                  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                  version="2.0">
            <xsl:output  method="xml"
                        indent="yes"
                        omit-xml-declaration="yes"/>

            <xsl:template  match="/">
                  <xxx>
                        <xsl:value-of  select="/aaa/bbb/ccc"/>
                  </xxx>
                  <yyy>
                        <xsl:value-of  select="/*/*/@*"/>
                  </yyy>
            </xsl:template>

      </xsl:stylesheet>

      <aaa>
            <bbb  r="rrr">
                  <ccc>12</ccc>
            </bbb>
      </aaa>

      <xxx>12</xxx>
      <yyy>rrr</yyy>