The experiments I conducted on the two devices from Samsumg - GT-I9190 mobile phone and tablet GT-P5200, first save the contacts there is a way to staff (the book menu - Import / Export to export the card SD). Now you have to turn off the device, with this you can do it yourself, and then have to press and hold the button combination (Google gives different options) for the phone [Power+ Volume (+) kn.HOME] tablet [Power+Volume (+)], hold until any picture (tablet is in the center of the screen will show the "Samsung GALAXY Tab ........"), and then forward to seeing what the type
We are interested in the item wipe data / factory reset the volume button (+-) to move the cursor to this item and confirm the power button and the device will think
!!ATTENTION!! this option will delete all your data.
We are interested in the item Yes - delete all user data volume button (+-) to move the cursor to this item and confirm the power button when the device is not long reverie announce on the work and show a menu with the previous Scrin select reboot system now.
The device will start the pre-configuration and installation (date, time, connection to Google, Samsung, etc.)
So, good luck.