I have been importing a lot of basketball game dvd's onto my macbook and then transferring them to my external hard drive. I have been importing those dvd's into imovie to create a highlight movie. Now my computer says that I don't have enough room to import any more movies into imovie. After I am done pulling the clips I want from the basketball movies, I delete them from imovie and the only thing left in imovie is the short clips I copied. How do I get my computer to free up the space that those imported dvd's are taking up so I can import movies into imovie for editing? (Does my question make sense?) Thanks!