XSLT: How to change an attribute value during ?

Question

I have an XML document, and I want to change the values for one of the attributes.

First I copied everything from input to output using:

Answer 1

You need a template that will match your target attribute, and nothing else.

  This is the value

This is in addition to the "copy all" you already have (and is actually always present by default in XSLT). Having a more specific match it will be used in preference.