Help! reset ZJT-H1

Hi Guys,

I need a help How to hard reset my new Chinese Phone. ZJT-H1

It's a 1 GHz MTK 6820 processor with Android 4.0.5. More details

Model ZJT-H1
Android 4.0.5
Screen 3.5" Capacitive Touch Screen
CPU MTK 6820/1GHz
2G/GSM 900/1800 MHz
Extended Memory Support TF Card up to 32GB Max
Camera Dual Camera(Front 1.3MP/Rear 5MP with Flash Light, Support Video record)

And also how to updat to the officiel frimware
Any help :(