In order to hard reset a Ericsson GF 388, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Ericsson GF 388 device will be brought back to the default configuration of a brand new device.
1. Start by turning on the phone.
2. Open Settings and Master Reset.
3. You will be asked to enter the phone's lock code (0000 by default). Do it.
4. Done.