new: how to change the values of a list of attribute

i've forgot to delete unnecessary attribute from the result XML.

so, i've this xsl file suggested by mikael kay that doesn't works to change my
xml that follows the xsl file. the result that i wolud obtain is posted to the
end.

XSL file

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet exclude-result-prefixes="#all" version="2.0"
xmlns:mets="http://www.loc.gov/METS/"	xmlns:mix="http://www.loc.gov/mix/"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:rd="http://cosimo.stanford.edu/sdr/metsrights/"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:f="http://example.com/f">


<xsl:output indent="yes" method="xml"/>

<xsl:template match="@* | node()">
<xsl:copy>
<xsl:apply-templates select="@*, node()"/>
</xsl:copy>
</xsl:template>

    <xsl:variable name="g" select="//mets:div[matches(@LABEL, '^Pagina
        [0-9]+$')]"/>
    <xsl:template match="*[. intersect $g]/@LABEL">
        <xsl:variable name="n" select="f:index-of-node($g, ..)"/>
        <xsl:attribute name="LABEL" select="concat('Carta ', if ($n mod 2 =
            0) then concat(($n + 1) idiv 2, 'v') else concat(($n + 1) idiv 2,
'r'))"/>
    </xsl:template>

    <xsl:function name="f:index-of-node" as="xs:integer*">
        <xsl:param name="nodes" as="node()*"/>
        <xsl:param name="node" as="node()"/>
        <xsl:sequence select="1 to count($nodes)[subsequence($nodes, ., 1) is
            $node]"/>
    </xsl:function>

</xsl:stylesheet>

XML file

<mets:div LABEL="Canto VI">
<mets:div LABEL="Pagina 56">
<mets:fptr FILEID="file.00059"/>
</mets:div>
<mets:div LABEL="Pagina 57">
<mets:fptr FILEID="file.00060"/>
</mets:div>
<mets:div LABEL="Pagina 58">
<mets:fptr FILEID="file.00061"/>
</mets:div>
<mets:div LABEL="Pagina 59">
<mets:fptr FILEID="file.00062"/>
</mets:div>
<mets:div LABEL="Pagina 60">
<mets:fptr FILEID="file.00063"/>
</mets:div>
<mets:div LABEL="Pagina 61">
<mets:fptr FILEID="file.00064"/>
</mets:div>
<mets:div LABEL="Pagina 62">
<mets:fptr FILEID="file.00065"/>
</mets:div>
<mets:div LABEL="Pagina 63">
<mets:fptr FILEID="file.00066"/>
</mets:div>
<mets:div LABEL="Pagina 64">
<mets:fptr FILEID="file.00067"/>
</mets:div>
<mets:div LABEL="Pagina 65">
<mets:fptr FILEID="file.00068"/>
</mets:div>
<mets:div LABEL="Pagina 66">
<mets:fptr FILEID="file.00069"/>
</mets:div>
</mets:div>

XML that i would obtain

<mets:div LABEL="Canto XI">
<mets:div LABEL="Pagina 59">
<mets:fptr FILEID="file.00116"/>
</mets:div>
<mets:div LABEL="Carta [59v]">
<mets:fptr FILEID="file.00117"/>
</mets:div>
<mets:div LABEL="Carta [60r]">
<mets:fptr FILEID="file.00118"/>
</mets:div>
<mets:div LABEL="Carta [60v]">
<mets:fptr FILEID="file.00119"/>
</mets:div>
<mets:div LABEL="Carta [61r]">
<mets:fptr FILEID="file.00120"/>
</mets:div>
<mets:div LABEL="Carta [61v]">
<mets:fptr FILEID="file.00121"/>
</mets:div>
<mets:div LABEL="Carta [62r]">
<mets:fptr FILEID="file.00122"/>
</mets:div>
<mets:div LABEL="Carta [62v]">
<mets:fptr FILEID="file.00123"/>
</mets:div>
<mets:div LABEL="Carta [63r]">
<mets:fptr FILEID="file.00124"/>
</mets:div>
<mets:div LABEL="Carta [63v]">
<mets:fptr FILEID="file.00125"/>
</mets:div>
<mets:div LABEL="Carta [64r]">
<mets:fptr FILEID="file.00126"/>
</mets:div>
</mets:div>