Hi, Steven
When you log in as the system admin, if you go to Settings > Antispam, on the Options tab you'll see the Actions (...) button. Click that and from the dropdown select Import Spam Settings. You can just drag and drop the JSON file in the modal that opens and SmarterMail will add that new JSON file. Here's a screenshot of what it looks like:
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com