Are you asking how to replace the entire headlight assembly -OR- how to replace just the headlight bulb?
Just the bulb.
how to replace water pump on 2001 ford focus
The Ford focus can have LED will headlights. The LED headlights do not come standard on the vehicle and will need to be an aftermarket addition.
I need daigram of 2001 ford focus se serpentine belt
How do you replace front wheel bearing on a ford focus
By going to a garage
See the answer for "How do you replace the drive belt in a 2000 Ford Focus?". The procedure is the same.
About $1000 each.
There are 4 screws that hold it on.
Material and labor... about $400.
You have to take half the car apart to replace the heater core
Try making sure that your headlights are off before opening any doors including the hatch. Is the door ajar light on and only turns off if your headlights are on?
From the inside, behind the panels.