Imovie Library

I have run out of space on my HD and am trying to clean my act and of course the HD. I see that my imovie library is 299GB in size but when I open Imovie there is nothing there ;-0

Can you tell me where they are so I can actually see each movie delete the files I don't want?

I was able to use the old IMovie with IDVD but I have not made peace with the new version so I've kind of abandoned the program. Now I cannot even understand how to see the files.

Thanks!

Teresa