this is pretty vague but I purchased a set of sidemarkers on amazon, switchback leds that had to be wired to the headlight. I found when trying to install the sidemarker with the bulb socket already in place, it will make it difficult for the sidemarker to mount properly. I found what worked best was unplugging the bulb, installing the marker (peel back the fender liner a little further), reach around and replug it in. Hope that helps!