Storage space is one of the biggest problems for laptop users. You can run out of those bytes in no time at all, especially if you fill your laptop with multimedia files like music and movies – the types of files that you keep and manage using a multimedia manager like iTunes.
If the problem is only moving everything inside the iTunes folder to the external drive, a simple cut and paste would solve it. The trick however is to keep everything intact. Nobody wants to re-fill hundreds (or thousands) of song information, re-assign all the ratings, re-paste all lyrics and re-hunt for the cover art. The only thing that should be different after the move is the location.