You should look into reading up on G3X/G3X Touch Installation Manual, Section 35 (touch) or Section 34 (non-touch). It's all described in detail there.
If it's already running you can hold nearest + menu + back buttons all at once and it will start to reboot and from here you can hold down the menu key.
You should look into reading up on G3X/G3X Touch Installation Manual, Section 35 (touch) or Section 34 (non-touch). It's all described in detail there.