HI again @nicholasgriffin
I have been following that tutorial too and as the installation of that module is thought for a normal installation on apache it won't work with the apache installation of bitnami (due all the apache files are on
/opt/bitnami), so I'm afraid that the only way to install a new version of mod_pagespeed is building it from sources.
In this tutorial: https://developers.google.com/speed/pagespeed/module/build_mod_pagespeed_from_source
is explained how to build it.
If you follow it, you should take care to configure this environment variables in the
... # see Makefile for more options
I hope this information is useful for you. If you have any other question, please do not hesitate to let us know.
Thank you and best regards,