How to remove (all) calendar entries.

I added to default calendar a couple of events, re-occurring weekly. Well now after latest update google calendar started to work, so now I don't need default calendar contents anymore. Still even I uncheck default calendar from "manage calendars" , event reminders do alarm from that calendar. And because I set those to re-occur weekly there are a lot of them... So how can I remove all entries from default calendar at once ? Removing calendar app and re-installing it did not help.