How to change the collation of an MS SQL database

NOTE: While changing the collation, no users should be connected to the database.

In order to successfully change the database collation you will need to set your database to a single-user mode, change the collation, and set it back to a multi-user mode.

You can copy, paste, and run the following T-SQL script to achieve this:

SELECT name, collation_name FROM sys.databases; 
GO 
ALTER DATABASE [DatabaseName]  SET SINGLE_USER WITH ROLLBACK IMMEDIATE; 
GO 
ALTER DATABASE [DatabaseName] COLLATE CollationName; 
GO 
ALTER DATABASE [DatabaseName]  SET MULTI_USER; 
GO 
SELECT name, collation_name FROM sys.databases; 
GO

SELECT * FROM fn_helpcollations()