How to add or change "login name" on users

How is it possible to add or modify "login name"
through "Enterprise Manager" on an existing users of a
database.
The "login name" has been created but I need to effect the
changes on the users. An example is either to either add
or change the "login name" of the user "dbo".
Advise would be appreciated.sp_change_users_login
--
Tibor Karaszi, SQL Server MVP
Archive at: http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sqlserver
"topokin" <bimosekin@.hotmail.com> wrote in message news:04b601c3c540$3a4d2920$a101280a@.phx.gbl...
> How is it possible to add or modify "login name"
> through "Enterprise Manager" on an existing users of a
> database.
> The "login name" has been created but I need to effect the
> changes on the users. An example is either to either add
> or change the "login name" of the user "dbo".
> Advise would be appreciated.