So, if you are trying to change the collation of a database and getting error 5030, this is much likely because you cannot change the collation of a database when it is in Multi_User mode. In this case, you should try to run the following query.
-- the following line sets the database to "Single User" mode
ALTER DATABASE DBNAME SET SINGLE_USER WITH ROLLBACK IMMEDIATE
-- the following line sets the new collation
ALTER DATABASE DBNAME COLLATE COLLATIONNAME
-- the following line sets the database back to "Multi User" mode
ALTER DATABASE DBNAME SET MULTI_USER
DBNAME: Database name
COLLATIONNAME: New collation’s name. E.g.: Latin1_General_CI_AI
