Increase Memory Limit PHP

I am a total novice so I apologise for my possibly very basic question, I have a GoDaddy Managed Wordpress site, and I need to increase my php memory limit, I have no clue how to do this or where to go to do this, I can access phpmyadmin page and after that I am lost as to where to go next. Could someone please give me some advice?

many thanks in advance - paula