First, nice name (my son's name is also Hunter)!
Depends upon what kind of car, the amount of corrosion, the age of the original distributor cap, and how aggressive one is in doing so. But Sanding? Heavens no!
The first suggestion I would have would be to use CLR and an old toothbrush to remove the primary corrosion, then use either an eraser used for removing ink, and/or an emery board to buff it up. You should, I'm sorry, your friend
should, do the rotor as well. But be careful with the contact for the ignition coil, most are made of carbon, not brass or copper.