There are two methods to the factory reset.
If you cannot access the Settings Menu, use this method:
First, turn your tablet off. Then, power the tablet back
up by holding down the volume (either + or - ) and power buttons
simultaneously. Continue holding the volume button until the screen says
"Booting tablet in recovery mode." This will give you a picture of an
Android. Tap the android, and you will be given a screen with several options.
Move between the options with the + and -, and select with the power button. Go
to the option for Factory Data Reset and select it. Scroll down to `the Yes,
and then the tablet will erase its memory back to factory settings. Once it has
completed, select Reboot Tablet Normally.
If you can access the Settings Menu, use this method:
Open the settings menu. On the left hand side scroll and
select Backup and Reset. Select Factory Data Reset, then select Erase Data. Then
the tablet will erase its memory back to factory settings. Once it has
completed the tablet will reboot normally and allow you to start over with the
Android Start-up Screen.