You can backup your database in the Maintenance section of your Admin panel for SMF. Just copy your files from your website to your hard drive to back them up. You download TinyPortal from this website, and then you find it on your hard drive when you go into the package manager. If you have mods installed then it will most likely fail in some aspects. But you can always remove the mods, install TP and then try to reinstall your other mods.