Plug the monitor into the motherboard and boot your computer. Then when something comes up, like the ASUS logo, hit "delete" or whatever it says to hit when it comes up. This should take you into the BIOS.
Now in the BIOS, you can do alot of things, like overclock your 2700K (which I hope you did not just buy for gaming) and you can also do some other stuff you will probably learn later.
Also in the BIOS, you can set the onboad graphics to be disabled. Now I don't know how to do it off the top of my head, but I'm sure if you navigate through enough windows you can figure out how. There's also videos on Youtube, and you can always refer to the motherboard manual.
Once you have figured out how to disable it, then you can press F10 to save and restart the computer.