A:This question is very good.You can look at the pictures bellow.There are main two kinds of design ways as the followings. you should be sure you need to change the car led bulbs .On the back of the car led lamp you'll see a three-pronged connection covered by a piece of rubber. If you see a small, plastic, i usually black knob on the back of car led lamp,it is the time for you to replace the car led lamp.