Samsung SGH-T359FBATMB - Manual (Page 125)

Changing Your Settings 122
Master reset
From this menu you can reset your phone and sound settings to the factory default settings.
1. From Idle mode, press Menu
➔
Settings
➔
Reset settings
➔
Master reset.
2. Enter your phone password and press Confirm.
3. Press Yes to reset your settings or No to cancel.
4. Press Back to return to the Settings menu.