when shut off head lights won't turn off

I whould like to do it myself but just don't know where to start.changed out door switch to no avail,don't know where relay is.how to backtrak from headlights.thanks for any info...

Hi, The ideal way to address this is using a wiring diagram and voltmeter. Determine how power is getting to the lights by tracing it back from the bulbs to the switch. You can get a wiring diagram with one of the online DIY repair manuals by ALLDATA or Mitchell. You can also try watching some videos online about basic electrical circuit diagnosis. I'm not a fan of throwing money away by guessing at what parts "might" be causing the issue...but you can always try cheap used parts from a pick/pull junkyard if you're going to take this approach. Good Luck