Here's how you can add or remove applets in Linux Mint 13 on the Cinnamon desktop.
1. Click the Settings Applet on the panel.
2. Click Add or Remove Applets.
3. The Cinnamon Settings menu for applets will appear.
4. Uncheck the box next to the applet you want to remove from the panel.
5. The applet will disappear from the panel.
6. If there's an applet you want to add, just click the checkbox next to it and it will appear on the panel.