how to reset the bios in the Lenovo Y560?

[Feodosii9962]

In general, after I reinstalled Windu did not want to include a discrete graphics card drivers installed, but a piece of hardware in the device manager as a standard VGA adapter. And of course , the laptop worked on integrated graphics.
In bios have turned on a discrete piece of iron , resulting in the monitor goes off completely. "Machine" includes running Windows, but the screen is black.
Attention to the question !
how to hard reset the BIOS on this laptop? Battery pull there or a connection from what ....