Q: How do I replace a headlight bulb on Mercury Cougar?
A: First of all, open the hood and disconnect the negative cable from the battery. Proceed to reach behind the headlight assembly and then unplug the electrical connector, employing a screwdriver to hold the clip out of the way. Also, you will be required to grasp the bulb holder and turn it counterclockwise to remove it. Lifting the holder assembly out is necessary to access the bulb. Push in and rotate bulb counterclockwise to remove it. To install it into your holder rotate it clockwise. Have your bulb holder installed in a headlight assembly.