(# Dikkat! Eğer 2. satırdaki soapenv, xml'dekinden (soap, sp, vs..) farklı ise eklediği yeni alanları namespace'li ekliyor)
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
version="1.0">
<xsl:output encoding="UTF-8" indent="yes" method="xml" version="1.0"/>
<xsl:strip-space elements="*"/>
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="soapenv:Body/child::node()" >
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
<kullaniciAd>1</kullaniciAd>
<sifre>2</sifre>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
---alternatif
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:S="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:ns0="http://ws.sgk100wsV2.sgk.gov.tr/"
version="1.0" >
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes" />
<xsl:strip-space elements="*" />
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()" />
</xsl:copy>
</xsl:template>
<xsl:template match="/S:Envelope/S:Body/*[1]">
<xsl:copy>
<arg0>
<xsl:copy-of select="//*[local-name() = 'arg0']/text()" />
</arg0>
<arg1>kullaniciAdi</arg1>
<arg2>sifreDegeri</arg2>
<arg3>arg3 degeri</arg3>
</xsl:copy>
</xsl:template>
<xsl:template match="/S:Envelope/S:Header">
<xsl:copy-of select="/S:Envelope/S:Header" />
</xsl:template>
</xsl:stylesheet>
XML