How do you change the alternator on a 2003 Ford Focus SE?

It isn't easy for a tyro. Please go to Trak Auto, Auto Zone, Pep Boys or NAPA, and get one and follow the instructions to a TEE. If you don't get the belt tension correct, you're in for boucoup problems, trust me!! You also need a belt tensioner tool to get the belt off first. We had to take a guard from under the wheel well to reach it from under the car. Then you have to remove the radiator reservoir and the power steering fluid reservoir. After removing the two long bolts holding the alternator in and unplugging the wiring and ground wire it wouldn't budge. We finally tapped it out with a ball peen hammer very carefully. The next problem was there wasn't enough room to remove it. We unhooked a wiring harness nearby and with a special fuel line tool removed the fuel line and pushed it back to the fire wall. After all that it barely came out. Putting a new one in took one person on top and one underneath to tap it it to position because it is a tight fit between its mounting bracket. I wouldn't recommend tackling this job by your self. Also make a drawing or have a schematic of the way the serpentine belt fits around all the pulleys.