1. Click on the Opera icon in the top left corner of your screen.
2. Then move the cursor over the More Tools tab, and then click on the Clear Browsing Data or simply press CTRL+Shift+Del.
3. Select Empty the cache option from the list and the time period for the selected options to be obliterated (Delete Cache from 1 hour, 1 day, 1 week and etc.)
4. After you are done with your selection, click on the Clear Browsing History button.