Free Up Database from unwanted NetFlow collection

o,

I recently installed an Eval copy of NPM 10.2.2 and NTA 3.9.  Win 2003 - SQL 2005 Express (limited to 4 GB)

I added 3  Routers exporting 8 NetFlow Interfaces and I decided to drop Router-3 from netFlow collection, and also couple of netFlow  interfaces from the 2 remaining routers.

Q1. How to free up my database from All Router-3 NetFlow collected traffic (I wan to keep Router-3 SNMP traffic) ?

Q2. How to free up my database from the 2 NetFlow interfaces Collected data , but keeping their SNMP collected data ?

Thank you