Please note that the following steps will erase all data from your phone!

1. Backup all your personal data
2. The option is under:
'Settings' --> 'Privacy' --> 'Factory Data Reset'
3. Tap 'Reset Phone'
4. You may be required to enter password, confirm by selecting 'Erase Everything'

If the above doesn't work or the phone is frozen, you may want to try hard reset.

To hard reset Evo 3D:

1. Backup all your personal data
2. Turn the power off. If the phone is frozen, remove and reinsert the battery.
3. Press and hold the 'Volume Down' button.
4. Press and hold the 'Power' button; wait for the device to turn on.
5. Select 'Clear Storage' from the menu by pressing the 'Volume Down' button.
6. Press and release 'Power' button.
7. Confirm by selecting YES - Volume up (Volume down = NO)

Once the reset is complete, the phone will reboot itself to a clean factory state.