After purchasing the Pro version, you will get a zip file (woostify-pro.zip) on your My Account page.
You can install the Pro version like doing with a normal plugin by going to Plugins > Add new > Upload
After activating Woostify Pro plugin, just simply go to Appearance > Woostify Options and you can see the options to enable all the pro modules here. You can also disable the module that you don’t want to use.
You can see a blank to fill the license key on the sidebar. This Woostify pro key is for activating the update and support feature.
Please note that Woostify Pro addon requires Woostify theme to activate and install!