This is a simple process, really.
People>Me>Tap your current profile picture>Select new profile picture.
Of course, this is with the built-in People Hub, which means you can do this simultaneously for every social network+Microsoft Account you have on the phone.
Should your social network not be supported by the People Hub, just download a client (be it official or third-party) for the social network, and work from there.
People>Me>Tap your current profile picture>Select new profile picture.
Of course, this is with the built-in People Hub, which means you can do this simultaneously for every social network+Microsoft Account you have on the phone.
Should your social network not be supported by the People Hub, just download a client (be it official or third-party) for the social network, and work from there.