I assume you have backed up those files, just in case.
If so, then you are good to go. If you are using Windows Vista or Windows 7 then I would just use that OSes "Disk Management" utility.
Others here recommend a utility like Partition Magic.
However, a question for you. Why do you want to partition? What will that achieve?
Mark
How do I create a partition on my external hard drive without removing all my files stored inside?

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