Go to your Profile and access the user Group Tab or click this link: Usergroup Tab

Now use the button "Apply to Usergroup".

A Moderator must acept your Request, wait a moment or yell in the Shoutbox.

1: Click on Group Leader

2: By Applications click on the green pen

3: Set "Application status" to "Accepted"

4: Submit

Special Note:
You can manage the Member group by clicking the green pen left of Member.