In order to hard reset a T-Mobile Dash, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
T-Mobile Dash device will be brought back to the default configuration of a brand new device.
1. Turn off the phone.
2. Press both Softkeys and Power buttons simultaneously.
3. Press 0 to confirm the operation. Phone should now restart.
4. Voila! Done.