how do I replace ball joints and wheelnbearings

Your best bet would be to let a shop handle it. Once you start tearing apart the front end, you need to have it aligned. If you want to do it yourself, go to Autozone and pick up a Haynes or Chiltons repair manual. You will then have the step by step procedures with pics. If the wheel bearings are pressed on, you will have to bring it to a shop unless you own a press. I would quickly call the Ford dealer and ask them if they are pressed bearings.....I know the '98 Fords were pressed on bearings, not sure about the 99's.