But after I changed the server.port in lighttpd.conf I noticed the comments that said "any changes...will be on the next update" so I also put server.port in external.conf which I'm guessing had no effect.
Indeed after my recent update the conf file was replaced and server.port was set to 80 and after that I could no longer access the web console.
I changed the syntax in external.conf as suggested server.port := 480
But still I can't access the web console at http://pi.hole/admin or by using the IP address.