[MEI-L] Converting specs to schema

[TW]

How do I convert the big specifications source file
(mei-2011-05-source.xml) to RNG or XSD?  I easily get lost in HTML
documentation I generated from the full RNG.  I'd like to strip some
modules to simplify things.  As the module information is lost in the
RNG, I want to modify the original, then go via RNG and XSD to HTML.
(Is there a more straightforward way?)

Thanks!
Thomas