How to change another users session with php [closed]

I am going to explain this with an example Jake and Kevin own a company called facebook, they want a means of advertisement so they create an account named facebook and immediately after creating it both of them login to the account and start advertising, later Jake wanted to change the name of their company to stackoverflow so he went to the settings and did just that, problem now is that on jakes laptop the name is stackoverflow but on kevin’s laptop the name is facebook How can i make it that at the point of submission my php script checks if the user name for anyother session is facebook and change it to stackoverflow