click on your 俱乐部 on your profile... then you'll have the 列表 of 俱乐部 you're in, then 你 click unsubscribe and its done ^^ But hey... u dont have to insult JB on the JB spot, 粉丝 will obviously hate 你 a lot ;)
On your profile, go to your clubs. Locate the Justin Bieber club, and there should be a word 下一个 to it that says "unsubscribe". Click that and it should remove you. Hope it helps!!