

Iranian people need to overwhelmingly decide to do it
The issue with this is that it’s terrifying for the vast majority of people to try and resist a murderous autocratic regime, especially when you’re not sure if enough other people in your vicinity will (successfully) have your back to make sure that you’re not kidnapped and tortured or shot right in the street.
Ideally, we should have an international nonviolent organization that could arrive wherever needed to help a population get out of the shackles (with no strings attached)
The population. This theoretical organization would need to be safe guarded enough that the people would believe they can be frank in expressing their wants without being afraid of repercussions from their regime or external forces. (so for example, if the people say they want socialism, with things like cooperatives and local gardens, then the people from the international organization would help them achieve that)