Remove iMovie Media in iMovie. In iMovie, select Media tab and select iMovie Library to reveal your copied media files. You can select all media that appears then right-click and choose Delete Media from Event. You will receive a confirmation pop-up message to delete the media. Despite the fact that Apple keeps the Mac Library folder hidden from users, it’s good to learn how to show the Library folder on Mac. You may need to access the Library folder when you need to clear cache, remove the app’s leftovers, edit preference files manually, etc.

Memory is precious 💎 What do you do when you need more?

Check Your iPad’s Storage

The first thing you’ll want to do is to check what exactly is taking up space in your iPad's storage. You can find this out in your iPad’s Settings:

Open Settings in your iPad

Make sure you are in the General section in the sidebar
Tap Storage & iCloud Usage
Under the Storage section, tap on Manage Storage

Before You Delete

The two most common solutions to clear storage space on your iPad is to delete photos/videos from your photo library or to uninstall apps. Before you delete anything though, make sure that you know how to backup the files you would like to keep. For example, you can keep a backup of your photo library on iCloud.

Deleting Photos

Here is an easy way to delete multiple photos on your iPad:

Open Photos in your iPad
Tap Select in the upper right corner
Tap on the photos you would like to delete
Tap on the trashcan icon in the upper left corner
When you’re sure, tap Delete Photos

Clean Imovie Library

Uninstalling Apps

Having a lot of apps on your iPad can take up a lot of space so be sure to uninstall apps that apps you don’t use in order to keep your iPad clutter-free:

Tap-and-hold on the app you would like to uninstall
Tap on the x in the corner of the app you’re uninstalling
Read the message carefully and once you’re sure, tap Delete
Press your iPad’s home button once you’re finished uninstalling apps

Don’t want to uninstall apps?

If you don’t want to uninstall some apps but don’t have any other way of freeing up memory on your iPad, make sure that you check the saved files in that app. Try deleting some decrepit projects in iMovie or old presentations in Keynote!

Hi RoseBriar,

You should be able to move Event videos from your library on the internal hard drive to an external one, with this article:

To copy or move Events to another hard disk:

Clean Out Imovie Library

Connect a compatible external hard disk drive to your computer.
In iMovie, click the Hard Disk button to see all available hard disks, which are listed in your Event Library.
The button is located in the upper-right corner of the Event Library.
Select the Events you want to move or copy.
To select more than one Event at a time, press Command as you click Event names.
Do one of the following:
- To copy the Events, drag them to the icon of the hard disk, in the Event Library, you want to copy them to.
- To move the Events, hold down the Command key as you drag the Events to the icon of the hard disk you want to move them to.
  The Events are moved, and they’re deleted from the original location. Any projects using clips from the moved Events refer to the clips at their new location. This means that the hard disk to which you have moved the Events must be connected to the computer where the projects are in order for you to play or further edit the projects in iMovie.
  If you’re moving a large amount of video at once, this process may take several minutes.

Unless the information about your OS version or iMovie version needs to be updated here, this should work for you. If not, can you tell me the version of iMovie you are using?

Thank you for using Apple Support Communities.

How Do I Clean Up My Imovie Library

Cheers,

Sterling

Jan 13, 2015 7:04 AM