It isn't possible to change a 潮流粉丝俱乐部 username, sorry. I guess it'd be confusing for other members if they got used to associating 你 with a particular name, so 你 just need to be careful to pick a name you'll keep liking when 你 join. The only option would be to 删除 your current account and start a new one - but then you'd lose all your current fans, your gold, medals, the association with your contributions etc.
潮流粉丝俱乐部 doesn't allow 用户名 changing. I learned that picking a 用户名 based off one of my current interests may not have been the best idea. I mean, it was at the time, but interest can fade. So, if you're wanting to a start a new account, try picking a name that's not based around your interests.