In order to hard reset a Sony Ericsson F500i, 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 F500i device will be brought back to the default configuration of a brand new device.

1. Turn on the device.

2. Starting from the Home screen, go to Menu > Settings > General > Master Reset.
3. Phone will now reboot and restart. Done!