To deauthorize your iTunes, follow these steps:
1. Open the iTunes application on your computer.
2. Click on the "Account" menu in the menu bar at the top of the screen.
3. Select "Deauthorize This Computer" from the drop-down menu.
4. Enter your Apple ID and password when prompted.
5. Click on the "Deauthorize" button.
Once your computer has been deauthorized, you will no longer be able to play content purchased from the iTunes Store on that computer. However, you can still play content that was imported from other sources, such as CDs or DVDs.
If you ever want to reauthorize your computer, you can follow the same steps and click on the "Authorize This Computer" button instead.