OK we all seem a bit confused, and the help material isn't at all clear to me. Can we try again: I have iMovie'13 updated from iMovie'11. I want to move the entire data off my Mac hard drive and onto an external hard drive. I created New iMovie Library on the external drive, no problem. I copied all the Events(?) from the old iMovie Library to the new one. That seems to have worked fine, all the events are able to be viewed from the New iMovie Library.
But, the New iMovie Library file is only 25MB in size, so as noted above it is only pointing to the actual clips which remain located on my Mac hard drive. So how to get those clips, events or whatever the source data is called onto the external drive and free up the space as intended?
In iMovie, I now have five items listed under the heading "LIBRARIES" being (1) iPhoto Library, (2) All Events, (3) All Projects, (4) iMovie Library, and (5) New iMovie Library. The trick, I assume, is somehow getting all the events in All Events moved, as the Events contain the actual clip data (don't they?).
I tried to drag and drop them into the New iMovie Library, this doesn't work at all: the cursor just selects a rectangle of multipe events. There is no right-click context menu to Move or Copy. The menu option File > Move to Library remains greyed out. So how do I get them moved?
What does the "Consolidate Library Media" option do I wonder...?