Overwriting built-in packages

[Nathan Van Ymeren]

Hello all,

I've been searching and reading documentation for about 2 hours now, and
haven't been able to find what I'm looking for.

I'm running Debian, which ships GNU Emacs with org-mode 8.2.10 and I would
like to overwrite this builtin package with a newer version (from melpa or
whichever repository).  What is the simplest, most correct way to do this?

Please help!

Thanks,

Nathan