Is it the headlamps themselves that are dirty, or the plastic covers which streamline the car?
If the plastic covers have become filmy, scratched, or yellowed with age, you'll probably have to replace them.
If it's the headlamps that have become dirty, find out how to remove and replace the plastic covers so you can clean their glass lenses. Sealed-beam headlamps were a real advance over the bulbs, reflector pans, and separate covers on older cars.
There so many videos on YouTube, like this
an old school trick to clean head light lenses is cheap toothpaste not gels or anything the basic all white paste.. it has silicon in it to shine teeth so in turn a bit of the paste and a polish pad on a drill cleans them up pretty good..
Toothpaste does wonders!
My car headlights are realy dirty
