My 8310 is falling apart. my friend has one too, and will give his to me. I swapped out the sim card and the memory card, but the settings, emails, passwords, etc stayed with the phone. Also, these phones are used for business.
So, question is: how to swap phones without losing data and leaving data behind?
Your friend will have to call his carrier and release his pin. Then you can associate that pin with your account. Until he releases the pin, you will continue to receive his mail and will be unable to configure your own.