I don't think you have any access to his phone, until you manage to hack it.
My Google accounts password is hacked and The hacker signed in and synched my google account in his android device. So now all my contacts are synched with his contacts in my account. Later i found a way to delete my account. But still my contact stays in his phone.please suggest if there is a way to remove my contacts from his phone. Any help is very much appreciated.