The Add-ons Manager also offers a convenient interface to manage extensions, themes, and plug-ins. Extensions can be enabled, disabled or uninstalled. If an extension is configurable, its configuration options can be accessed via the Preferences button. In the Appearance tab you may Uninstall a theme, or activate a different theme by clicking Enable. Pending extension and theme installations are also listed. Select Cancel to stop the installation. Although you cannot install Plug-Ins as a user, you may disable or enable them with the Add-ons manager.
Some add-ons require you to restart the browser when you uninstall or disable them. In such cases, after clicking either of these actions, a Restart now link appears in the add-ons manager.