You probably have the old 7" incandescent sealed beam lights that have been around from the '50s. They can easily be replaced with 2 piece non-sealed beam H4 lights. As long as you stick with the lower wattage (equal to old sealed), the wiring should be adequate (i.e. 55-60 watt - higher capacity separate 80 watt bulbs are available but require a relay with heavier wiring for best result and safety). I like the German Hella Vision Plus.
These have better lens optics and a whiter halogen bulb. You can up wattage of bulbs or replace with LED bulb (if you find a shallow replacement bulb).