How do i move my downloaded movies on apple tv to an external hard disk drive?

Hello imabuku99,

The supported method of backing up your purchases from the iTunes Store to an external hard drive would require a computer.

If you have a Mac, your media library is automatically included in that backup. You can use Time Machine to back up to an external storage device using the steps in Back up your Mac with Time Machine.

"Select your storage device as a backup destination

Your Mac might ask if you want to use the storage device for Time Machine backups. If it doesn't ask, follow these steps.

1. Open Time Machine settings from the Time Machine menu  in the menu bar.
2. In Time Machine settings, select your external storage device as your backup destination.
3. If the storage device contains Time Machine backups from another Mac, you might be asked to claim the existing backups so that they become part of the backups for this Mac. Or you can choose to start a new backup instead."

If you have a PC, you can Download and use iTunes for Windows 10 and back up your iTunes media folder using the steps in Back up and restore your iTunes library on your PC.

"Here are some things to know

Your iTunes library, a database that's made up of all of the music and other media that you add to iTunes for Windows, is organized into two iTunes library files and an iTunes Media folder.

Before you back up your media:

• Consolidate your iTunes library.
• Redownload any previous purchases, like music, movies and TV shows, and more. The only way to back up your purchased media is to download your purchases to your computer."

If you'd like to share feedback with Apple about this, feel free to submit that here: Product Feedback - Apple

Take care!

imabuku99,

You're most welcome. Thank you for using Apple Support Communities.

Have a great day!