You should have the files
Airio.con.1
Airio.srv.1
Copy and paste them and rename them to
Airio.con.2
Airio.srv.2
Change the 2 new files to the details for your second server.
It should connect both the servers after a few minutes but if not just restart Airio.
I think free Airio can connect 3 servers but I might be wrong we have 7 connected on a pro airio.