Help needed to modify SEPA XML

Hi. I've trying to create a new version of the IBY_SEPA.xsl file where the InitgPty is hardcoded into the file instead of selecting the Tax Registration Number or Legal Entity Registration Number. In the standard Oracle file, we have the following (extract):

    <InitgPty>
      <Nm>
        <xsl:value-of select="InstructionGrouping/Payer/Name"/>
      </Nm>
      <Id>
              <OrgId>
               
          <xsl:choose>
            <xsl:when test="not(InstructionGrouping/Payer/TaxRegistrationNumber='')">
                                                    <Othr><Id><xsl:value-of select="InstructionGrouping/Payer/TaxRegistrationNumber"/></Id></Othr>
            </xsl:when>
            <xsl:when test="not(InstructionGrouping/Payer/LegalEntityRegistrationNumber='')">
                                                    <Othr><Id><xsl:value-of select="InstructionGrouping/Payer/LegalEntityRegistrationNumber"/></Id></Othr>
            </xsl:when>
            <xsl:otherwise>
                                                    <Othr><Id><xsl:value-of select="InstructionGrouping/Payer/LegalEntityInternalID"/></Id></Othr>