The generic procedure is to take it to the plater. They will bath it in acid to remove rust and old chrome. Then weld a sheet metal patch and grind the excess to leave it as smooth as you can. Take it back to the plater so they can give it afirst nickel plating. Then, buffing wheel until it's polished, und a last chrome plating.
If they are still available from Honda, it can be cheaper to buy new ones.
Raul