How to change username?

Hey I am new to this whole thing (clearly) how do you go about changing your username? Do you need to spend X amount of time online? Do you need to use "money" how does this work?

Thanks guys

I'm pretty sure you have to buy premium to change it. I think Supreme is the level with the option.

Note that changing the username is an action which makes more sense for established accounts, who wish to change the username while retaining their old posts (and credits!). For a newish account it would probably be simpler to create a new account, and consider that the old one doesn't exist any more,