Do you have a PDF file that you would like to attach to a reference already in EndNote?
Steps
You can also go to File > Import or drag and drop a PDF from your computer, or set up the PDF auto-import function. See videos below for how to do this.
To access the PDF of an article
1. Highlight the reference in your library
2. Double click on the reference to open up the summary window. Click the drop-down box of the title of the PDF at the top of the window to see options for downloading the PDF.