Moving your iMovie Events and Projects from one drive to another isn't as effortless as it ought to be--but it's still worth doing.

iMovie events can fill up your hard drive fast. We'll show you the right way to move them.

Difficulty Level: Difficult

What You Need:

>> iMovie '08 or later (part of iLife, $79, apple.com)
>> Footage stored in Events within iMovie
>> Two or more iMovie Projects already created
>> An external hard drive

iMovie’s a fantastic editing program that does a good job of organizing your footage. It’ll let you save your media and iMovie Events on external drives if you like, but what if you run out of space and need to move your clips to an even bigger drive? Apple’s engineers did think of this eventuality and provided an easy solution for it, but it only works well if you create one Project per Event and don’t use clips from multiple Events in a single Project. Otherwise, you may encounter problems--and fixing them can be trickier than you might think.

We’ll walk you through the easier, built-in way to move your iMovie files around; then we’ll guide you through the process of fixing your Projects and Events (if needed) once they’ve reached their new home. This should also help you understand why some of your clips may have become unlinked--rendering them invisible to iMovie even though you haven’t deleted them--and then fix that problem too.

1. Drive Migration

Command-drag a Project to your external hard drive (circled in red), then choose the second option in the dropdown.

Connect an external drive to your Mac and launch iMovie. Reveal your Project Library by going to Window > Show Project Library. Scroll down the list to your external drive’s icon at the bottom. Command-drag an existing Project onto it, and a dropdown will appear, giving you the option of moving just the Project or including the Events used in it too. Choose to include both the Project and Events. Repeat the procedure for your other Projects. If you only create one Project for each of your Events, you won’t have to do anything else. However, if you pepper your work with clips from multiple Events, you’ll end up with multiple copies of the same Event on the external drive because each Project is linking to a different version of the same footage, wasting valuable disk space.

2. Finding the Events

Our external drive's iMovie Events folder has two copies of our Screencast Event.

Open your external drive in the Finder. You’ll see two new folders, called iMovie Events and iMovie Projects. Each duplicated Event has a number added to it, making it easy for you to see which ones will soon become superfluous. To know which Project links to the duplicated Event, go back to iMovie and open one of the Projects you just moved. Right-click (or Control-click) one of its clips and choose Reveal In Finder to see which Event that clip is linked to. If it’s to the copied Event, make a note of the Project’s title. Your aim now is to merge the duplicated Events so you can safely delete the unneeded one and free up some space. Quit iMovie.

3. Unearthing the Project File

Select Show Package Contents to see what's in your Project file--which is really a package of files.

Go to your Desktop and create a new folder (File > New Folder). Name it “Alteration.” Still in the Finder, go to your Movies folder, select iMovie Projects, and right-click (or Control-click) the Project file bearing the missing link. Choose Show Package Contents. This opens a new window displaying all the files that make up your Project. You need to alter the one called “Project.” Option-click it and drag it to the Alteration folder on your Desktop. Option-clicking makes a copy of the file you’re dragging so you still have the original, just in case something goes wrong. Leave the window open.

4. Terminal Access

When using the Terminal, always double-check your spelling before pressing Return.

It’s time to launch the Terminal. It’s located in the Applications/Utilities folder, but you can quickly launch it by clicking on the Spotlight icon at the right edge of your menubar and typing Terminal. The Top Hit should be the program you’re looking for, and since it’s already highlighted by default, hit the Return key to launch it. Type cd Desktop/Alteration and press Return to make Terminal focus on the content of that folder. Next, type plutil -convert xml1 Project and press Return to change the Project file’s format to xml. This will make it easier to read and alter.

5. Using TextEdit

We're replacing all references to the duplicate Event (Screencast 1) with references to the main Event (Screencast).

Right-click (or Control-click) your modified Project file and choose Open With > TextEdit from the contextual menu. You can scroll through your file, and you’ll find references to media stored on your hard drive scattered throughout. Since the duplicated Event is called [iMovie Event] 1 (where [iMovie Event] is the Event’s actual name), go to Edit > Find > Find to reveal the program’s Find And Replace window. Type [iMovie Event] 1 in the Find field and [iMovie Event] in the Replace field; then click Next. You’ll jump straight to that name’s first instance, where you can then click Replace to change it, or just click Reply All. When finished, save your work and quit TextEdit.

6. Back to the Terminal

Changing this back to a Project file, the reverse of what we did in Step 4.

You now need to turn your file back to its original format. To do this, go back to the Terminal window. If you didn’t quit the program at the end of Step 4, it should still be running and focused on the Alteration folder. Type plutil -convert binary1 Project and press Return. You may notice that your file’s size will have noticeably shrunk back to its original size. You can now quit the Terminal.

7. Replacing the Original

If the Project is trying to link to the Event you deleted, you'll see a warning--instead of footage--in the Preview pane. We're all good.

Go back to the window that shows the content of your iMovie Project package, which you revealed in Step 3. Move the original Project file to a safe location (just in case) and replace it with the version you just modified. Move the duplicated Event to the trash and launch iMovie again. If you did everything right, all your Projects should now link to clips in the one Event on your external drive. Revel in all that disk space you’ve freed up… before you fill it again!