1) Every Forum has a tab listed under development team zone. You have to click on Join Moderation Team tab.
2) You will be directed to another page where you have to fill up a form.
3) If your entry is accepted you will be notified through Join Moderation Team. All you need to do is click on the status in the same tab.
p.s: You can also change your answers anytime instead of filling up another form in future.