Entering BIOS with external monitor, ASUS X555LB laptop

[Exsecutor GG]

Hello, I've cracked the display on my laptop Asus X555LB and currently I'm using external VGA monitor. I would like to reinstall Windows, but I cannot enter BIOS since external monitor doesn't work till OS is loaded. I've tried to toggle combination Fn+F8 when I am in BIOS, but external monitor still doesn't work. I've read that I need to set external monitor as primary in BIOS, but I cannot enter as the laptop display is cracked. Can someone help with that or provide instructions how to set external monitor in BIOS, so I can do blind walk through

 

[geofelt]

A graphics adapter will by default put the bios screen on the first connected monitor.
Can you possibly disconnect the internal cable that controls the laptop screen so that I will not be detected?
That way, the graphics adapter will select your vga attached monitor.