The person who created the campaign will always be a GM, but Mark G. has good advice on how to promote a second (or third, fourth, etc) person as GM. Any GM can rejoin the game as a player by choosing the "rejoin as player" button at the bottom of the settings tab in the campaign: <a href="https://wiki.roll20.net/My_Settings#Exiting_and_GM_View_Modes" rel="nofollow">https://wiki.roll20.net/My_Settings#Exiting_and_GM_View_Modes</a>