Moving iTunes movies to external hard drive

I want to move my iTunes movies, but not my iTunes music, from my MacBook Pro to an external hard drive to free up space on my computer. The hard drive is connected to my Mac via a thunderbolt connection. What are the exact steps needed to do this? Do I need to create a special directory on the external drive first, and then move the movie files to it, or is it a simple drag and drop procedure. Over time I am trying to make my Mac a media center, containing all of my CDs (over 5000 CDs) and my movie collection, both purchased iTunes movies, and HD movies that come with purchased DVDs.