contact support
How do people change there username more than once?

Yes, it's possible. You just contact staff through a contact support ticket, and ask for a username change. they'll usually comply if it's a reasonable request.
Obviously you can't keep changing it, im pretty sure staff won't let you spam username changes.

This is very pathetic that people use fake profiles and names related to other known personalities. Many of these profiles are there to post abusive comments and implement hidden agendas on behalf of some people. Fake profiles are good if someone wants to play chess without revealing who they are. But, if fake profiles are used to spread hidden agendas and to abuse people , those fake profiles should be closed. This is my opinion.

my man sounding like he got this from one of the buddhas teachings
Haahaaahaa! You there again? Budha told me yesterday to tell you this. Since you don't take advice from strangers, I thought of posting here. But finally, it reached you. And also the Laughing Budha told me that you will even post a comment after reading this.

This is very pathetic that people use fake profiles and names related to other known personalities. Many of these profiles are there to post abusive comments and implement hidden agendas on behalf of some people. Fake profiles are good if someone wants to play chess without revealing who they are. But, if fake profiles are used to spread hidden agendas and to abuse people , those fake profiles should be closed. This is my opinion.
ABSOLUTELY.
Thanks!

Contact support
I changed my username 3 times
@dev_the_pro (7/28-8/10)
@1g4_1-0 (8/10-11/1)
@grobandwins (11/1-11/23)
@brawlstars_beast64 (11/23-PRESENT)
Title says it all. My friend @woodpusher28 used to have two names. Noah131k, and 1b31-O. How can you change your username more than once? Just curious