How to rename FTP user? and FTP user should be local Admin or Domain user Admin

Hi ALL;

Do you know if FTP user should be local Admin or Domain user Admin?

after rename and change FTP user pass, do I need to restart Microsoft FTP services or restart server to start all services and dependency automatically?

I want to rename FTP user and change pass, waht are step and location to rename FTP user?

do I need to create a new one?  if possible to rename option?

do I need to change pass from 2 side?

1.Control Panel\System and Security\Administrative Tools
Internet Information Services (IIS) Manager

and

2.Control Panel\System and Security\Administrative Tools