Painting metal dash

I would like to paint the metal dash in my 1970 swinger, dash pad has aready been removed and painted with sem color coat.also gages and other have been removed. I prefer not to remove the metal dash frame from the car. It is currently a flat green I wish to paint it black can anyone advise me on a good method to go about this task. should I sand it? what about primer, what kind should i use. what kind of paint ? I do not have all the equipment to spray it. so I will have use rattle cans Thanks.