DECLARE @Sql	nvarchar(255),
		@uname	sysname

DECLARE cur CURSOR FOR 
				SELECT u.name
					FROM sys.sysusers u
						INNER JOIN master.sys.syslogins l
							ON u.name COLLATE Cyrillic_General_CI_AS = l.name
					WHERE l.isntname = 0
						AND	u.sid <> l.sid

OPEN cur
FETCH NEXT FROM cur INTO @uname
WHILE @@FETCH_STATUS = 0
BEGIN
	SET @Sql = 'ALTER USER [' + @uname + '] WITH LOGIN = [' + @uname + ']'

	PRINT @sql
--	Exec (@sql)

	FETCH NEXT FROM cur INTO @uname
END
CLOSE cur
DEALLOCATE cur