I am going to do the rear brakes on my friends 98 windstar. Do I need any special tools to do this job. Any problems that could arise. I have the basic brake tools.

probably the only thing on these cars that hasn't been made more difficult to work on. Seems like on these the more prone to failure the more difficult to work on.
bentwings

Be sure to pick up a srevice kit for the rear brakes( new springs, lock tabs, etc). Also make sure the rear wheel cylinders are not siezed.

while you're in there, make sure the antilock sensors are clean and not caked in rust. I just had a problem with mine, so it's worth checking while you're at it.

If you have the rear drum brakes.....I just did mine....and posted pictures.....
http://community.webshots.com/album/201931518cScpNK

I replaced the drums as one was out of round.