Changing the address of a primary name server

[Thomas Schulz]

I hope that this is not too far off topic, but I expect that the people
here will know the answer.  We are currently providing the primary name
server for our domain with our internet service provider providing the
secondary name server.  We will soon be changing to a new service
provider and the IP address of our primary name server will have to
be changed.  The last time I did this, the whole job could be done
through Network Solutions.  It appears that this has changed.  Looking
at their web based account management tool, I can see how to specify
which name servers are to be used for a domain, but not how to specify
the IP address that a name server lives at.  How does one modify the
record for a registered domain name server?
-- 
Tom Schulz
schulz at adi.com