Technically, most of the time i use Maplat::Helpers::ConfigLoader, which in turn uses XML::Simple. But reading/parsing (most) XML files by looking at the screen works just as well.
For complicated cases cat|grep|less and/or vim are also good options to quickly find the one relevant option in huge directories full of XML stuff :-)
"I know what i'm doing! Look, what could possibly go wrong? All i have to pull this lever like so, and then press this button here like ArghhhhhaaAaAAAaaagraaaAAaa!!!"