When you reassemble the brake rotors to hubs, wire brush and if needed, lightly sand the rust off the hub. Also clean up the mating surfaces of the rotor including the large center hole. Then lightly coat the mating surfaces of the rotor with an anti-seize paste. This will make it a little easier for the next person to remove the rotor. Of course, check the thickness of the rotor and replace if it is at or below minimum thickness or if the inner drum surface is damaged. Try not to invent too many new cuss words when you attempt to install the new E-brake shoes.