Kiwi database in MSSQL server is growing very big

I am managing the Kiwi syslog database in MSSQL server. This database is growing rapidly and its current size is around 400GB.

1. Is there a way to filter those un-important logs? If yes, how to do it?

2. Is there a script/procedure to purge the old data at the MSSQL server end?

Thanks.