if your headlamps are plastic like the JDM headlamps...use 1500-2000 grit sandpaper and wetsand to blur. take some 3M rubbing compound, or some plastic polish to buff it out. comes out looking like new. my headlamps and corners were yellow and dirty beforehand.

here's a pix of mine after the polish.




the headlights and corners came out like brand new. this method is only for plastic headlamps...not glass.