Do you want change facebook page username and not able to change so long. Don't worry follow this step than you can change Facebook username easily.
First your change admin of your facebook page Click-pacge-setting-page role-assign new page role-type name-enter role
then you can try for change Facebook page username and its change.
Thank you, for telling that will help in change the facebook page name. I try many thing to change the username of my facebook page but fail everytime, but now I get to know through your blog this is the new way for me. I will try this and will let you know what I find in this, moreover I also want to know of there is anyone in your surrounding who knows about block chain development services usa if yes so kindly do let me know about it.