When you make a purchase from The Preset Factory, you will be given access to download an Installer (for MacOS and Windows) for the product(s) you have purchased. You will also be given a unique License Key, a 16-digit code that you must enter into your install to validate it. Without a valid License Key, you cannot install your presets.
Your License Key can be found on the Order Confirmation page after your purchase. It will look some like this: GH78-0892-ABH7-10BT
The video below details where to find your License Key, and how to download and install your presets: