How to span when media is already on the portable drive
I have a MacBook Air with iTunes and all my music. Due to size limitations of the SSD drive (500GB), I have all my movies on a portable seagate hard drive (3TB). I am not sure of the steps to have the iTunes library find the movies and videos on portable drive, or span to it. I get it when you have a new empty drive, but this one already has the media loaded.