I tried to change the <xsl:value-of select="1"/> to <xsl:value-of
select="0"/> using an xslt processor. Is this possible using saxon or
should I use an other approach?

It is possible using Saxon (or any other processor), *but* you should
use another approach. Have an xsl:param at the top-level (as Martin
suggested, not as you wrote it), and then, instead of hardcoding the
value, write:

If you invoke the saxon9.jar (or saxon9he.jar) without any parameters,
you'll get a command-line usage explanation, including parameters.

--
Michael Ludwig