To delete documents for a contact, follow the steps below:
1) Click the Contact tab.

2) Locate the contact from the list or use the contact search at the top of the page. Click on the pencil icon to edit the contact.

3) Select the Documents tab from the menu.

4) Find the document in the list and press the delete icon on the right hand side of the document. A confirmation box will appear, press Okay to delete the document.

This will delete the document from this tenant and it will also be deleted from the Documents section.