http://msdn.microsoft.com/en-us/library/ms174269.aspx
Excerpt from books online:
Moving a file to a new location
The following example moves the Test1log2 file created in example A to a new directory.
Note:
You must physically move the file to the new directory before running this example. Afterward, stop and start the instance of SQL Server or take the AdventureWorks database OFFLINE and then ONLINE to implement the change.
Copy Code
USE master;
GO
ALTER DATABASE AdventureWorks
MODIFY FILE
(
NAME = Test1log2,
FILENAME = N'c:\t1dat2.ldf'
);
GO
Manu