Change Name?Xemnas

Hey!
My name is Ldunedai in game, let me ask, im trying to change my name but idk if i can change my name with item or i have to do this on the site.
How i can change my name?I want to put the name "Xemnas" on my Blood-Elf Paladin (my unique and first character). Who change the name its me or i have to ask for you guys?Im a acctive player, thanks for attention
(ps: ignore my bad english, im from Brazil)

On site, go to:
My account > services > select your realm and character > points > change name