Deleting attachment from form
Click
Formsin the left menu.Click the red circle paperclip icon next to the form you wish to download an attachment from
OR
within the relevant form, click
Morein the top toolbar and selectFilesfrom the dropdown menu.

A popup will appear with all of the files currently attached to your form.
Click the three dot icon in the row of the relevant attachment and Select
Deletefrom the dropdown menu.