Lenovo B580 switchable graphics

Hi..
I have Lenovo B580 (20144) laptop with switchable graphics cards Nvidia 610M & Intel HD 4000. I want to disable switchable graphics and i want to use only nvidia graphics card.What can I do in this regard?? Can I upgrade my BIOS to get more options.
Your help is urgently required please.
Thank you for your interest

Note: Bios Ver. H1ET73WW(1.16)