Upgrade from Free to Premium

Very much a rookie in installing Joomla templates, but managed to do it with the Hotstart Installation (with Demo). It's working and I'm manipulating the demo version to make make site. I needed to upgrade to the premium version to be able to get the scrolling top carousel, so I clicked the link and purchased the template.

I don't know what to do now to "unlock" the premium version. I don't want to start over - I've done too much work already.

Help please.

Overwrite template files you did not change, so you can skip template_css.css and files like that