Here's the step by step instruction on how to factory reset the LG Optimus T that clears all data and restore its original factory settings.
Note: the result of this process will delete all data stored including third-party application installed from the LG Optimus T. However, this process may or may not delete data stored on the microSD memory card. Please make a back up copy of all the personal data before proceeding.
On the main home screen, try this..
1. From the main home screen, select Menu
2. select Settings, then the Privacy
3. select the Factory data reset
4. select Reset phone
5. Enter the password if prompted, then confirm by selecting Erase everything
Try a button combination, If the phone is frozen:
1. Turn the power off first. If your LG Optimus T is frozen, pull out the battery and reinsert it back again
2. Hold the Home and Volume Down button
3. Press and hold the Power button until the handset device turns ON
4. Just follow the on-screen instructions to reset the device
All data stored including the third-party applications installed will be deleted from the LG Optimus T. Once the restoration or wipe is complete, the phone will then reboot to its factory fresh default state settings.