XML::Simple (and not LWP::Simple) is simple to use.
As for installing it, I don't see what the problem is
with typing the usual make/make test/su/make install
mantra.
I am afraid that if you want to process XML in Perl you
will have to install XML::Parser, including the expat
library. Unix users usually have gcc around and XML::Parser
comes pre-installed with the Activestates port on windows.
So it really shouldn't be a problem.
The only real problem that you might come accross is actually
that you might have too many versions of
expat installed, as some of the Apache tools come with
their own, dynamically linked and slightly incompatible
version of the library. See the XML::Parser review for
more details. By the way a team including Clark Cooper,
the maintainer for XML::Parser, Apache people and even (gasp!)
Python developers (Python XML tools are also based on
expat) is working on the problem.