To upload a media release you will need to upload the PDF as a 'document' in the CMS. Then copy the link to this document. You can access the Document library by clicking on Document on the content tab.
Once you have uploaded a document you are presented with the unique URL for that document:
On your Media release page, write the title of the media release, highlight it, select insert link in the top formatting bar and paste the link to your document.
