'''Turn off''' the tablet completely.
Press and '''hold''' the '''Volume Up''' button.
While holding the '''Volume Up''' button, Press and '''hold''' the '''Power''' button.
Once the tablet turns on (you can tell because it vibrates) release the '''Power''' button but keep holding the '''Volume Up''' button.
Once the '''Recovery Menu''' boots up, use the '''Volume''' buttons to navigate to '''Wipe Data/Factory Reset'''.
Then press the '''Power''' button to select it, then confirm it and it should factory reset.