This document explains how to clear the cache and cookies in Mozilla Firefox 29+.
1. Click the Menu button near the top right corner of the screen and click Options.
2. To clear cookies click on the Privacy tab and click on remove individual cookies. You can choose to delete individual cookies or all of them.
3. To clear the cache click on the Advanced tab and click the Network sub-tab. Under Cached Web Content click the Clear Now button.
4. Click OK to finish.