Delete your temporary Internet files and cookies - Mozilla Firefox
Please follow the steps below to delete your temporary internet files and cookies from Mozilla Firefox.
1. Within Mozilla Firefox, go to the Tools menu and select Options.
2. From the Options window, click the Privacy tab, then click the Clear Now button.
3. In the Clear Private Data window, select each of the available checkboxes, then click the Clear Private Data Now button.
Please note: By clearing your private data you will be removing all stored data on your computer relating to websites, including any usernames/passwords that you may have saved (in instances where certain websites allow you to "automatically" sign in). Please ensure that you know all of your login details for any websites that you visit before you do this.