1979 KZ750 forks

Hello, My friend has R1 forks, what do i need to do to hav the conversion fit? like do i need new calipers/rotors/wheel etc?

You need the entire front end, calipers/rotors/wheels, and a custom steering stem made and pressed in to replace the stock R1 stem.
And then the fun starts. Got speedo? What about the rear? Going to run 17" radial on the front and 18" bias on the rear?