To clear cache and cookies using advanced options in Firefox please follow the steps below:

  1. On your computer, open Firefox
  2. At the top right, click the Menu button, and select Settings
  3. In the left menu, choose Privacy & Security
  4. Scroll down to the Cookies and Site Data section, and click Clear Data
  5. Ensure both checkboxes are checked, then click Clear at the bottom right
  6. At the confirmation popup, choose Clear Now