How do I replace the front axle on a 2000 ford focus

It should be similar to the process described in the link below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-9.html#post1691894

The trick is often separating the lower ball joint from the control arm. After that, it's pretty straight-forward.