1. Log in to ArcGIS manager with arcgismanager account at http://myserver:8099/arcgismanager/main/login.jsf
2. Log in to ArcGIS REST API Admin page with the arcgismanager account at http://myserver:8399/arcgis/rest/admin/login
3. Log in to ArcGIS Server REST API with a generic user account created in ArcGIS Manager under Security > Users