My friend gave me this phone for free, with no service, and I try to get onto Google Play Store, and it will only let me sign in via the email he used when it was his. Well I even made am account on the phone (sync'd email to the phone) and it only let's me attempt tp login using his old account. How do I change it to mine? And also I will attempt to factory settings IF it doesn't require a plan or a SIM card like iDevices. Thamks!