I am not sure, but there might not be anythihg to download. It is an online service.
Go to https://exportpdf.acrobat.com/SignIn.html and Sign In with your Adobe ID.
For details and getting started, see http://kb2.adobe.com/community/publishing/898/cpsid_89847.html
Unlike other conventional products ExportPDF is a derivative of Adobe Acrobat however instead of being offered as a standalone software this product is offered as SAAS(Software as a service). It is hosted on Adobe servers and you do not need to download the software. As Vikrant suggested you simply need need to sign in on the link mentioned and you can start using its features as per the plan you have purchased.