Change port numbers

Hi all, I’m new to using Octoprint and I would like to now how to change port 80 please can someone tell me if this can be done bearing in mind that I am a total beginner.

Assuming that you installed this on a Pi using the OctoPi image then you're looking to edit the /etc/haproxy/haproxy.cfg file on this line:

        bind :::80 v4v6