In order to hard reset a Sony Ericsson P1, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Sony Ericsson P1 device will be brought back to the default configuration of a brand new device.
1. Power up the cellphone.
2. Select Menu > Settings > General > Master Reset.
3. Select either Reset settings or Reset all.