In theory, if everyone has become selfless, there is no need for a man with a stick to create the rules or ensure compliance. No one will want to use a stick to push through rules which are to their advantage. People will simply cooperate with each other or help each other willingly where necessary.
Think of a group of friends or adult family, where people help each other and cooperate willingly, because they love each other. Hopefully you don't need to threaten your partner to do their share of the household tasks. You do it because you want your relationship to succeed and want to support each other.
The USSR tried to create this new man with a stick, propaganda and indoctrination during the dictatorship of the proletariat phase. They never achieved fully realized communism, where everyone willing works to the best of their ability and helps their commune succeed and the commune of communes that is a truly communist society succeed.
Smaller anarchist communes and experiments will try to do this organically. Everyone chooses to try to do their best and help the rest of the commune. It sounds pie in the sky, but it's not unlike what volunteer groups do. People believe in a common cause, and freely volunteer their time, because they believe in their shared goal, and enjoy working together.