Depending on the type of field you used for your upload element, there will be a few ways you can locate the documents your client attached to their template.
If it was a dataset element (which means the element on your template is connected to the profile) you'll be able to navigate to the Account Profile, click on 'Documents' in the upper right-hand corner, and review all documents here.
Check the box/boxes to download or remove certain files.
You can also view a list of attachments on the engagement through the engagement details panel.