Hard Reset SAMSUNG T320 Galaxy TabPRO 8.4 WiFi

First method:

1. In order to switch off your device press the Power key.
2. Afterwards press and hold together: Volume Up + Home button + Power button.
3. You should release held keys when an Android Icon appears on the screen.
4. Select "wipe data / factory reset" by using Volume buttons to navigate and Power button to confirm.
5. In the next step choose "Yes -- delete all user data" to confirm whole operation.
6. When the Recovery Mode appears again select "reboot system now".
7. Good job! The hard reset has just been performed.

Second method:

1. If the display is off, press the Power button to turn it back on.
2. Afterwards go to Settings and then to Backup & reset.
3. Tap Factory reset device and Reset Devive. 
4. Choose Erase Everything if you are sure you want to clear all your data. 
5. Select OK to confirm the whole operation.
6. Well done!

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.