Final answer:
To clear cache and cookies on Firefox, go to settings, select 'Privacy & Security', click on 'Clear Data', choose the time range, and click 'Clear.'
Step-by-step explanation:
To clear cache and cookies on Firefox, you should go to the browser's settings and select 'Privacy & Security'. Under the 'Cookies and Site Data' section, click on 'Clear Data'. A new window will open, and you should make sure that the boxes next to 'Cookies and Site Data' and 'Cached Web Content' are checked. Lastly, choose the time range you want to clear, which can be 'Last Hour', 'Last 24 Hours', 'Last 7 Days', or 'Everything'. Click on 'Clear' to remove the cache and cookies from your Firefox browser.