The job is simple.
Take your tire off break loose bleeder, loosen Cal bolt, Remove. Remove disc Reverse process..
Make sure to bleed the breaks. Pump,pump,pump hold brake petal down while someone releases the bleeder line and shoot air and fluid out. Do this until you just get fluid, No air. Maybe once, Maybe 4 times.
Call some aftermarket diesel places, Order slotted disc's.
Check the vendor list