To replace the head light bulb on F-150/250 and Expedition models follow the following procedure, Turn the hood open, now press at the back of the head light housing respectively, and push these clips upwards to take out the housing. For 2003 to 2006, do not remove the vertical bolt nearby the housing, however, unscrew it slightly; the rest two bolts are those which stabilize the housing at the top. For 2007 and later models there is no vertical bolt, it has been replaced by a horizontal bolt. Pop the headlight housing to reveal the bulb holding ring at the back part of the assembly, then turn the ring anti-clockwise to get the bulb holder out. Extract the bulb assembly and the retaining ring, then you shall pull the bulb out in a vertical manner with the direction of movement being from the socket assembly. To replace the bulb, do not touched the glass part and put new bulb in the proper place and fix the retaining ring and make it tighten. Take the headlight housing and adjust it back into position before fitting the retaining clips, operate the headlights before closing the hood. For the Navigator, the process starts as the hood is opened, the vertical bolt of 2003 to 2006 models is loosened and the top bolts are removed. Pull the cover off the headlight bulb and unscrew the electrical connection to the assembly; turn the retaining ring anti-clockwise to pull the bulb out. Pull off the old bulb, put in the new bulb without the coming into contact with the glass part and fix it. Last, connect the electrical connector, check the functioning of the headlight, and then shut the hood.