Hard Reset SAMSUNG I9195 Galaxy S4 mini

First method:

1. Power off your phone by holding the Power key.
   
2. Then press and hold together buttons Volume Up + Home button + Power button, and release this when you see logo Samsung.
   
3. Choose using Volume buttons option "wipe data/factory reset", and confirm that usingPower key.
   
4. Next confirm "yes" previous operation using Volume keys and Power key.
   
5. When this operation is completed, select option "reboot".
   
6. Done!

Second method:

1. Start by turninng on the device.
2. From the Home Screen go to Menu and then to Settings.
3. Tap Backup & Reset and then Factory data reset.
4. Afterwards find and select Reset device.
5. To confirm your choice select Erase everything.
6. That's all.

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