My factory very likes to show you a vedio where to put car leds to your information as below. Before put car leds, you need to identify car leds replacement are high beam, low beam, fog front light, turn signal, park or reverse light because some car leds are similar base types.

Second, please put gloves when you install car leds.

Last one, please also check very care of tightening plug and sockets of led car connections.