In general people provide a stylesheet that applied on the old version 
will give the new version.
The stylesheet is a variation of the identity template that adds some 
processing that deals with the changes. For instance the below 
stylesheet changes element a with element b:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
version="1.0">
   <xsl:template match="node() | @*">
     <xsl:copy>
       <xsl:apply-templates select="node() | @*"/>
     </xsl:copy>
   </xsl:template>
   <xsl:template match="a">
     <b>
       <xsl:apply-templates select="node() | @*"/>
     </b>
   </xsl:template>
</xsl:stylesheet>

Here it is a real world example, a stylesheet that converts from TEI P4 
to TEI P5:
http://www.tei-c.org/Activities/META/p4top5.xsl

Best Regards,
George
---------------------------------------------------------------------
George Cristian Bina
<oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger
www.---.com


Udo Ende wrote:
> Hi,
> 
> I have a set of XML files being (correctly) validated to a XSD file. No=
w I
> upgrade the XSD file and therefore I have to change the XML files.
> 
> What is the best way to automate the transformation of the XML files? A=
re
> there any tools that can do that?
> 
> --
> Udo Ende
> Dipl.-Math. Univ.
> Software Engineer
> 
> MID Enterprise Software Solutions GmbH
> Eibacher Hauptstr. 141
> 90451 N=FCrnberg
> Telefon: +49 911-968 36-24
> Fax    : +49 911-968 36-10
> E-Mail : u.ende@m...
> WWW    : http://www.mid.de 
> 
> 

From mike@s... Fri Feb 17 10:00:20 2006
Received: from lisa.w3.org ([128.30.52.41