Hello,
I never saw any official procedure for this script (as far as i know it is only official way to clean server events). You must execute this script using your usual tool (sqlplus , dbexplorer, ......) .
below feedback available on support site:
ClearSystemEvents.sql - This will clear all records from the systemevents table. Systemevents table is used as a log by DLP to record system events for troubleshooting. There is no ongoing provision for periodically clearing out this table. It will grow and grow and grow.
Regards.