Often I've been following a set of instructions for updating or resolving some problem. At the end of the instructions comes the final instruction: "Restart Firefox." I'm always mystified because I've never been able to learn exactly how one is supposed to "Restart Firefox."

Your instructions seem to imply that this is so elementary, that no further explanation is required. I'm sorry, but I've tried very hard, many times, over several years, but have never been able to find any information about how one is supposed to "Restart Firefox.