Just curious: why do you need a rebuild? You can just copy them and hack away. Use forms-samples-styling.xsl from the forms samples as a starting point
I was under the impression, so information I have read leads me to believe, that resource://org/apache/cocoon/forms/resources/x.xsl tresolves to files in the java class path and that these files are jar'd during the build process?!?, and as Jason said, the last thing you want to do, especially taking into consideration future migration, is hack away at these files.
regards
Andrew
