I did a google search and this is what I found:
http://www.samsung.com/Products/Mobi...files/t300.pdf
The default
lock code for your phone is the last four digits of your
phone number. You can enter a personal lock code or change the
lock code as often as you like.
To enter a new lock code:
1. Press to display the menu.
2. Press for Security.
3. Enter your current lock code.
4. Press for Lock Code.
5. Enter a new 4-digit lock code by pressing the numeric keys.
The
Reset option resets the phone and returns all options to the
factory default settings. All your Personal settings (Phone Book, Voice
Dial recordings, Messages, and Calendar) are not affected by
resetting your phone.
To reset the phone:
1. Press to display the menu.
2. Press for Security and enter your current lock code.
3. Press for Reset Phone. A confirmation displays explaining that
you will reset the phone to factory defaults.
4. Press to reset the phone
5. Press to cancel the operation.
6. The phone resets and restores the default settings, erases your
messages and then returns to standby mode.