Documents that have been attached to a Folio cannot be deleted, instead they can be retired. To retire attachments, navigate to the attachment that you want to retire, then click on the ellipsis located to the right of the attachment:
This will open up a menu with several options. To retire the attachment select retire:
This will remove the attachment from appearing in that field:
However the attachment is still available if needed. To get to it navigate to the attachments tab on that Folio and click on the search icon on the search bar. In the pop up box, change the status filter from Active to Retired:
You will now see all retired attachments on that Folio. You can also unretire the attachment from the options that appear by clicking on the ellipsis: