Attach Current Document to Task Process

I am building a workflow on a SharePoint document library. The workflow runs to get approval from users and then is copied to an approved library. I have it all set up and working but I am running into 1 issue. How do I attach the current item to the task the users are assigned? I can link to the task and I can get a link to the details on the document, but I cannot get it to open the actual document being reviewed. These seems like it should be logical as they don't need to review the metadata, they need to review the contents of the actual document. Without doing that, they cannot do their job. What am I missing?