When logged in, hover over "content" and click "files". Click the orange "add file" button and upload it as you normally would with any other file. Click next until you're back to the list of files. The one you just added will be at the top. Click the link to it under the "title" column.
This will show you the file on a web page. You will need to click the link to the PDF that is on the page in order to get the direct link for download.
Once you're on the page with your pdf displayed, click into the address bar and highlight the text from the right to the left all the way up until the end of your website name, including the ".com", as shown below. Copy only this part of the link.
Navigate to the page you want to add the PDF link to, highlight the text, and click the link button in the WYSIWYG as you normally would. Paste the full link for the PDF into the "link URL" field and save.
