Unfortunately at this time it is not possible to change a users name in the hosted environment.
If it is vital that the users name be changed, then we would recommend that you disable the existing user and create a brand new user record under the new name. This will mean that existing transactions are linked to the old account and the user will essentially be starting over.
If you would prefer, you can leave the user ID and user name as they are and instead just update the resource name and the email addresses linked to the account (if needed) to reflect the new name. The Resource name, is the name that shows in the top right when you log in and is used on transactions.
To update the Resource name, please see our article FocalPoint User's resource name is incorrect or needs changing.