I recently needed to change the SQL Collation to allow for a System Center Configuration Manager install, but I forgot to do this when I built the SQL Server. To change this after installing SQL, run the following command:
setup.exe /q /action=rebuilddatabase /instancename=mssqlserver /sapwd=yourpassword /sqlcollation=SQL_Latin1_General_CP1_CI_AS /sqlsysadminaccounts=domain\administrator
Note: if you need to see the command output, remove the /q. Also – use with caution, I ran this on an empty SQL Server with no databases on it.
For further information see: https://msdn.microsoft.com/en-gb/library/ms179254.aspx