Set or Change the Server Collation

https://msdn.microsoft.com/en-us/library/ms179254.aspx

• Make sure you have all the information or scripts needed to re-create your user databases and all the objects in them.
• Export all your data using a tool such as the bcp Utility. For more information, see Bulk Import and Export of Data (SQL Server).
• Drop all the user databases.
• Rebuild the master database specifying the new collation in the SQLCOLLATION property of the setupcommand. For example:
  Setup /QUIET /ACTION=REBUILDDATABASE /INSTANCENAME=InstanceName 
  /SQLSYSADMINACCOUNTS=accounts /[ SAPWD= StrongPassword ] 
  /SQLCOLLATION=CollationName
  

  For more information, see Rebuild System Databases.
• Create all the databases and all the objects in them.
• Import all your data.