https://github.com/LondonPM/London-pm-website
Send a message to virtuallysue at gmail.com or ask in the IRC channel (irc.perl.org/london.pm) for someone to give you access to the group google calendar (see http://london.pm.org).
Follow the instructions at https://guides.github.com/activities/hello-world/#branch to branch the LPM website, clone the banch to your machine, make changes, then git add, commit and push them back to github and finally create a pull request. Once your changes are accepted then updates are currently automatic via cron from the master branch of the github repo on the hour and half hour.
Too much trouble to maintain