This installation guide will show you how to install the bumper reflector LED lights on your 2014-up Lexus IS. You can find this under Lexus IS LED Bumper Reflector Lights (75-419).
Step 1: Remove the rear bumper. There are several clips that you need to remove as well. Be patient! You can check the forums for people who have attempted to remove the rear bumper to see where all the clips are located.
Step 2: After you remove the rear bumper, you get access to a 10mm bolt. Remove the bolt and remove the stock bumper reflector before you can replace it with the new LED bumper reflector.
Step 3: After you remove the stock bumper reflector you can remove the stock taillight.
Tap the corresponding wires. In this instance, this particular vehicle's wiring is as follows:
For the reflector: black is ground, green is parking light, red is brake light, white is turn signal.
Tail lamp harness: black is ground, red is parking light, green is brake, green with yellow is turn signal
Black to black, green to red, red to green, white to green with yellow.
Step 4: Extend the wires to the LED bumper reflector location. You can use T-taps to extend.
Step 5: Always test the bumper reflector LED lights before you put them back to make sure the taillights, parking lights, and turn signal lights properly function.
Step 6: Put the new LED bumper reflector back the same way you remove the stock bumper reflectors and test the LED lights again.