Reset DNS config - "do you want to set up DNS"

I have Server 5.0.15 running on El Capitan. I would like to configure the DNS service as the "Do you want to set up DNS" option, when setting the hostname. When I try to trigger the "Do you want to set up DNS" option by going through the change hostname wizard and clicking Finish, I only see a confirmation prompt, "Are you sure you want to change your server's host name?" I'm guessing this is because the Server initial configuration is already completed...

Two questions:

1. Is there a way to get the "Do you want to set up DNS?" prompt to appear, without doing a full reset of Server--can I do something to reset just the DNS service part of Server and get the prompt to appear?
   
2. Is it possible to manually configure the DNS service as it would be by the "Do you want to set up DNS?" prompt? I manually created a primary zone with the same name as the server's hostname, but when I tried adding a HOST record, leaving the Host Name field blank (trying to create a record with the same name as the zone name), I see a prompt, "A host name is required. This machine record cannot be created without a host name."
   

Thank's in advance!