<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
    <soapenv:Body>
        <root>
            <MyElement>content</MyElement>
        </root>
    </soapenv:Body>
</soapenv:Envelope>

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
   <soapenv:Body>
      <root>
         <NEW xmlns="http://ws.apache.org/ns/synapse">content</NEW>
      </root>
   </soapenv:Body>
</soapenv:Envelope>

<xsl:stylesheet xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:avintis="http://www.avintis.com/esb" extension-element-prefixes="avintis" version="2.0" exclude-result-prefixes="#all" xpath-default-namespace="">
    <xsl:output method="xml" encoding="UTF-8" indent="yes" omit-xml-declaration="yes"/>

    <xsl:template match="/soapenv:Envelope|soapenv:Body">
        <xsl:copy>
            <xsl:apply-templates select="*|text()|@*"/>
        </xsl:copy>
    </xsl:template>

    <xsl:template match="root">
        <xsl:copy>
            <!-- FIRST METHOD - THE METHOD I want to use! this will receive the  xmlns="http://ws.apache.org/ns/synapse" -->
            <NEW>
                <xsl:value-of select="MyElement"/>
            </NEW>
            <!-- Second methodworks - but I need to add xmlns="" to every element and there are a lot-->
            <NEW xmlns="">
                <xsl:value-of select="MyElement"/>
            </NEW>
            <!-- Third method works: But not very readable - I would prefer the first method -->
            <xsl:element name="NEW">
                <xsl:value-of select="MyElement"/>
            </xsl:element>
         </xsl:copy>
    </xsl:template>
</xsl:stylesheet>

<xsl:stylesheet xmlns="" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns="" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:avintis="http://www.avintis.com/esb" extension-element-prefixes="avintis" version="2.0" exclude-result-prefixes="#all" xpath-default-namespace="">
<xsl:output method="xml" encoding="UTF-8" indent="yes" omit-xml-declaration="yes"/>

<xsl:template match="/soapenv:Envelope|soapenv:Body">
    <xsl:copy>
        <xsl:apply-templates select="*|text()|@*"/>
    </xsl:copy>
</xsl:template>

<xsl:template match="root">
    <xsl:copy>
        <!-- FIRST METHOD - THE METHOD I want to use! this will receive the  xmlns="http://ws.apache.org/ns/synapse" -->
        <NEW>
            <xsl:value-of select="MyElement"/>
        </NEW>
        <!-- Second methodworks - but I need to add xmlns="" to every element and there are a lot-->
        <NEW xmlns="">
            <xsl:value-of select="MyElement"/>
        </NEW>
        <!-- Third method works: But not very readable - I would prefer the first method -->
        <xsl:element name="NEW">
            <xsl:value-of select="MyElement"/>
        </xsl:element>
     </xsl:copy>
</xsl:template>