With Magento 2.x, once you have re-uploaded and decompressed the FGXseal.tgz file on your server's Magento installation directory (as indicated on the FGX-Web portal), you need to run the following commands from the Magento backend in order to upgrade code and flush its cache:
bin/magento setup:upgrade
bin/magento setup:di:compile
bin/magento cache:flush