How to Delete Movies From the iPhone
The popular iPhone smartphone from Apple comes with disk-space size options of 16 or 32GB. Many users like to carry movie files on their iPhones, but the file size for a full-length movie can be well over 1GB. Combined with music files and other applications, an iPhone user can quickly run out of space. Fortunately, Apple included a way to delete movies from the iPhone to free up valuable disk space.
Tap the orange "iPod" button from the iPhone's home screen.
Navigate to the videos list by taping the "Videos" icon located at the bottom of the screen.
Swipe a finger left or right across the movie you want to delete. A red delete button appears. Tap it to delete the movie.