...
Log into the NPI client application.
Select Libraries > > Part Library.
On the Internal Part Number tab, select a part, then select the Documents tab on the right side of the window.
Select the Add button, locate and select the document you want to associate with the IPN, then select OK.
To open the file, select the View File button
(next to the Add button).If you decide to remove a file related to a part, select the file, then select the Remove
button on the Documents tab.
...