How do you change your URL?

I want to change mine from @pro_crastinate to @malicious_glee for Halloween!!

I want to change mine from @pro_crastinate to @malicious_glee for Halloween!! (It's not currently taken, but if it used to be and I'd get confused with someone, please let me know and I'll change my plan!!)

I want to change mine from @pro_crastinate to @malicious_glee for Halloween!! But idk how...

I want to change mine from @pro_crastinate to @malicious_glee for Halloween!! But idk how... So if you know, please tell me in the comments!!

I want to change mine from @pro_crastinate to @malicious_glee for Halloween!! But idk how... So if you know, please tell me in the comments!! Thanks!! <3