How is the stoning of the Jamarat on behalf of another performed if they have authorized me to do so?

It is permissible for the agent to stone on his own behalf, and then on behalf of his principal, for each of the three Jamarat (stone pillars) in one standing. He is not obligated to complete stoning on his own behalf and then return to stone on behalf of his principal, due to the lack of evidence necessitating that, and because it involves hardship and difficulty. Furthermore, this was not transmitted from the Companions when they stoned on behalf of their children or those among them who were unable.