Step 1: Free download iTunes Transfer. Install and run it.
Step 2: Make sure that you have installed and launched iTunes. After your iPhone/iPod/iPad connected to PC, Launch the program you will see the following UI. Normally, the program will search the device automatically. If the device is enabled, the files (songs/movies/photos) will be shown in the list. iTunes Transfer will auto scan your iPod, iPhone, iPad playlist and display what on your iPhone, iPod or iPad.

Step 3: There are many playlist on your iPod, iPhone or iPad. Take transfer songs from iTunes to Computer as an example. You can click one of the music playlist and the select the songs you want to export. Then click the button "Export". And you can export music from iPod Touch to iTunes.

Step 3: After you clicking the Export button, the following window will pop up, you can choose transferring songs to "Disk Only" directly. You can set the output folder at Advanced->Options before transferring.

Okay, you have finished how to transfer iTunes from one computer to another. It is so easy to do it.

Related Guide: How to Put Songs from iPod to iTunes?