IMHO, “an XML-parsing module” is the only way to go, and XML::LibXML is an excellent choice, since it employs a binary module that is quite likely to be the same one that was used to produce the file.   A very real consideration when dealing with XML files “manually” is that, sooner or sooner, the line-by-line format of the file will vary from whatever your hand-rolled program was built to expect.   (And it is most likely to do so at 4:45 PM on the evening of your child’s piano recital ... don’t miss it, Dad ...)

Therefore:   use a module/library.   Period.   There are actually several good ones to choose from ... XML::Twig is another good war-horse aimed especially at b-i-g files.   And leave us not forget XML::Simple.   Treat the XML file as an abstract thing, which the module magically knows how to manipulate for you.   You will be rewarded with a durable, long-lasting solution to the problem that won’t have to be revisited, no matter what the next XML file looks like.