Removing (or unlinking) a product clause from a system in your specification is undertaken in the same manner as removing any other clause type.
The separate support article How to unlink a clause in NBS Chorus provides instructions of how this is done together with additional information.
Please note: If you delete the product clause directly from the contents panel, you will create a broken link which will be highlighted in red.
The separate support article What are broken links and how to fix them provides further information.