If you want to disconnect an external hard drive from your PlayStation 4, follow these steps:

  1. Turn off your PlayStation 4.
  2. Remove the power cord from the external hard drive.
  3. Remove the USB cable from the external hard drive and plug it into a free USB port on your PlayStation 4.
  4. Turn on your PlayStation 4 and wait for it to recognize the external hard drive. Once it does, select “Storage” from the main menu and choose “Delete Content.” You’ll be asked if you want to delete all content on the external hard drive, just selected files, or only folders. Select “Just Selected Files” and press X to confirm. ..