answer:If you currently have an iTunes library on your laptop, open iTunes, click “file” then “export library” and export to your external HD. Next, close iTunes and hold the alt/option key (on a mac) while reopening the application. If you’re using a PC, look up “using multiple libraries” in the help menu to see which key to press. This will open a dialog for you to create a new library or choose a different library. Click “choose library” and navigate to the folder on your external HD. If your music files are scattered all over the place run a search for the file type(s) and then copy and paste all files to a folder in your external HD. Do the same thing with the iTunes library selection.