Open Settings
Tap Device Options
Tap Reset to Factory Defaults
Tap Reset to confirm
If the tablet is frozen, press and hold the Power button for about 40 seconds
When the tablet restarts, try the reset steps again
If you cannot access Settings, turn off the tablet
Press and hold the Volume Down button and Power button together until the recovery screen appears
Use the volume buttons to highlight Wipe data/factory reset
Press the Power button to select it
Confirm the reset
Wait for the tablet to restart and complete the reset