How do I clear my cache, cookies and history in Mozilla Firefox?

From time to time, you may be advised to clear your cache, cookies and browsing history to improve the performance of your internet browser.

1. Click on the Firefox menu (3 lines) on the top right hand corner
2. Click on Settings
3. On the left hand side, click Privacy & Security 
4. Scroll down to section Cookies and Site Data 
5. Click Clear data
6. A new dialogue box will open 
7. Click Clear Now and wait for that dialogue box to exit 
8. Close all open Firefox instances and therefore all tabs