You can install this module from the Modules tab in your shop (backoffice - modules and services - add new module). Simply upload the package you have previously downloaded from the Prestahop addons.
In some cases, usually due to hosting restrictions, it is not possible to upload the package from the Prestashop backoffice. In these cases you may use a FTP client to upload the module folder to the "modules" folder in your shop.
Once the module has been uploaded, it will show in the list of available modules for installation and you'll be able to install it in your shop.