Morlaf says:
there are a few guides on this website about this. Basically (and I apologize if you already know this) you narrate the story and we are the protagonists - or at least we feature in it. try and make it super - familiar (e.g. "Fire roared through the bifurcated city of ank-morpork.... and then we see a red wizard galloping on a horse, being chased by a suitcase on 100 legs while gold goings keep jangling on the cobbles.....") and keep it simple. we will create the chaos for you. Or anything else you like......
I'm well versed in GMing, but it is more the switch to a more clear turn-based play loop that I'm not that familiar with, but I will 100% figure it out. So that leaves the question, who wanna play?