Ninja File Uploader

Hello, PLEASE READ!!!! I need to create a form that has an uploader field. I already bought the plugin from Ninja form and I got to to work HOWEVER, within the admin area, I need to modify the file, delete, or upload another file. Let me explain this again... I created a contact form using NINJA FORMS. On the contact form I added a uploader file. I can see the link and see the file when I go into SUBMISSION page in the wordpress admin. However, I need to upload more files to the same name, or to replace the current file with another name. If you think you can do this, contact me please. We can discuss further. You MUST know NINJA FORMS.