There are two ways to unsubscribe from Firefox Push Notifications:

Option 1:

1. Access the website in the browser from whose push service you want to unsubscribe.
2. Click on the lock icon on the left side of the address field.
3. Go to Permissions and click on the small cross next to Send notifications.
4. To apply the updated settings, reload the website.

Option 2:

1. Open Options in the menu at the top right.
2. In the menu item Privacy & Security go to Permissions then to Notifications and click on Settings.
3. Select the appropriate website and click Remove Website at the bottom of the window.
4. Click Save Changes.