Like suppose if i want to go from despotism to democracy, and then back to despotism. Is there a menu that lets you change government, or can you only change when your advisor gives you an option to do so?
Press Select and choose 'Change Governments'. But note that if you change (in most cases) all your production (units, population, buildings, wonders, in ALL of your cities will stop. Then on your next turn, it will resume and your government will be changed to whatever it is you chose,