How Do You Merge XML Files?

I have my journal backed up in XML files, one XML file for each month. I'd like to be able to merge them into one file if possible, but I'm unsure how to do this. Simply concatenating the files doesn't work because the XML reader can no longer parse it. If there are any tools for KDE or Wine that I can use, please let me know. Same goes for Python or Perl scripts. I've tried KXML Editor but there doesn't seem to be a way to merge files. All of the files are in the same format (security, time, event, mood, etc). Is this feasible? I'll admit that my XML-fu is weak so don't slap me too hard, plzthx!

[EDIT: Never mind, I figured out how to do it manually... I just needed to remove the last "month" tag in all the files. Thanks anyway to neonleon.]