How do I move my files to external hard drive?

Hi there, OomBrood, thanks for posting here!

Just a small clarification before I provide you with the appropriate steps: do you use the desktop app on your end? 

If so, then you should be able to copy your Dropbox content from within your Dropbox folder, and paste them to your external hard drive. 

Now, if you wish to sync your external drive with Dropbox, you can always take a look at this Help Center article. 

I hope this helps, let me know if you have any questions!