<xsl:template name="replace">

    <xsl:param name="string" select="." />

    <xsl:choose>

      <xsl:when test="not($string)" />

      <xsl:when test="contains($string, ';')">

        <xsl:value-of select="substring-before($string, ';')" />

        <br />

        <xsl:call-template name="replace">

          <xsl:with-param name="string" select="substring-after($string, ';')" />

        </xsl:call-template>

      </xsl:when>

      <xsl:otherwise>

        <xsl:value-of select="$string" />

        <br />

      </xsl:otherwise>

    </xsl:choose>

  </xsl:template>

All you need do is call the template and pass your input into with $string param, in my case this was the ";". Then replace the <br/> tags with whatever you need to replace your input string with - easy!