There are people talking about how they changed their username. How do you do that?

You must buy an . You can buy it from the Cash Shop, or from a user shop. :)

Oh, now I get it. Thank you!!

No problem. :)

Also note you can change PET names too! You need a different item of course but it is really handy. On the 15th there is a cleanout of inactive user/pet names. :)