This article explains the steps on how to delete firewall in NSM-On Prem
Step 1: Log in to the NSM Management page using the server IP address.
Step 2: Select Manager View. Navigate to Firewall> Inventory and select the unit from the list.

Step 3: Click on Action tab and select Delete Firewall as shown below.

Step 4: Enable Force Delete. Click Confirm to delete the unit from NSM as shown below.
