If you have a local bike co-op, bring it in there.
Failing that, bring it to your local bike shop and ask to watch while they fix it. (It should be a one minute job, but call ahead as there may be a long line of people who dropped their bikes off before you.) They'll be able to show you how to do it, and will happily sell you the tool you need to do it yourself next time. Yes this costs more than you-tubing, but it ensure you get the right tool, and know exactly what to do on your sepcific bike. I find most bike mechanics are an awesome source of local in-person knowledge.
Pro-tip, wash your bike before you bring it in. Bike mechanics work on dirty nasty bikes all day, bringing yours in clean immediately put you in their good books.