In order to flush the Magento cache, you need to log in to the Magento admin panel and go to System > Cache Management. From this section you can refresh the different cache types in Magento, as well as use the four available buttons to:
Another way to flush Magento's cache is to manually delete its cache files. Magento stores its cache files in its installation folder > var > cache. To clear the cache manually, you need to delete all files inside var/cache. If you want to clear all sessions as well, you can do so by deleting everything from the var/session folder.