BDR: moving a node

Hello,

As a preamble, I'm running PostgreSQL 9.4 BDR on a Debian 9.

I'm moving a node to a new host. This is the node from which I started
BDR and had a second replicate join it.

I browsed the list archive, Googled all I could, found some threads and
Github issues, but came up with a grant total of no concrete answers.

When I say "moving", I mean I'm copying the entire filesystem with
PostgreSQL shut down, so I assume my data integrity is taken care of.
All I imagine I need to do is replace the DSN on the second node, which
in my carelessness, I set up using an IP address and not an FQDN.
I looked up Node Management Functions in the doc, but cannot come up
with the final set of instructions to perform an update of the DSN.

What is the process to update the DSN? I assume I'll have to relay the
changes in my pg_hba.conf, but do not understand, and don't want to
tinker, with BDR before obtaining some educated advice.

I apologize if my question comes across as dumb. I understand I have to
update bdr.bdr_connections, but how, and what do I restart? What about
the server that was moved, any updates needed there?

thanks for your help!