Changing the style of SGML stylesheets

Sorry if this is on the wrong board - Linux seemed the most appropriate!

I'm writing some documents with the Docbook SGML DTD, and I'm using openjade to convert to HTML for online copies. I'd like to be able to modify how the various SGML tags are converted; specifically I would like to be able to add some CSS code at the top of the file, to change the appearance of various tags. I can do it manually, but it's a pain having to redo it everytime I generate a new version from the SGML code.

Basically, can someone tell me how to modify the stylesheets? I've looked at lots of .dsl and .dtd files in /usr/share/sgml/docbook, and I've read [url=http://docbook.sourceforge.net/release/dsssl/current/doc/]Norman Walsh's docs on the stylesheets, but I'm none the wiser All I can find is info on how to change docbook-specific defaults.

My only alternative here is to write a Perl script to automatically do the jade work, then use regular expressions to change bits I like. But I'd much prefer to o it properly, if possible.