i just followed these intructions for the most part; once you get inside the HVAC; if you plan on soldering in LEDs you are going to need to desolder the bulbs that are in there. There is polarity with the LEDs so you will need to plug in the small more square connector (this is the harness for the lights) and touch your led to the points where the lamps once were. Make a note where your positive side(with resistor) is touching the board. you'll want to do this for all the led's you put in kinda a pain in the ass but patience is key.
Ive done this in both my cobalt and my jeep haven't had any issues with them yet my jeep's have been in for about a year and still no problems