You can replace an attachment (file or link) or edit its description on the Attachments tab of an open record window. In addition, you can modify file attachments when you are performing a workflow action, from the action window.
To modify an attachment:
On the Attachments tab of the object record window or in the Attachments section of the workflow action form, сlick Properties
or right-click the attachment and choose Properties from the pop-up menu. The Attachment Properties window opens.
To select another file, click the Replace button.To modify the link location, specify a new location in the Link field. To edit the attachment description, type it in the Description field.