Windstar,
Good to hear that you're getting somewhere. Don't be terrified that your tranny is low. It does have some miles on it and frankly they all leak a little bit. Be concerned if it's leaking a quart a month or something like that. I'd simply add some fluid and see what you get.
As mentioned in an earlier post, make sure you get a funnel for the job. They sell specific funnels for filling transmission fluid. The dipstick comes out, the funnel goes in the dipstick tube and you add fluid. I suspect, given what you indicated, that you are around 1-2 quarts low. Add 3/4 qt and recheck. (Make you cycle through the gears again, just to suck up any fluid and fill any air bubbles that you may have.) Keep adding until it gets to the top of the hash marks. On older models of the Windstar (1995 for sure), they recommended that you kept the fluid all the way to the top of the hash marks. They fixed the design, but it sure won't hurt to have it full.
If that gets you going, I'd address a change out a little later in the spring. As far as changing the fluid, Olepz, gave a good rundown. I would only add a few notes. It's not terribly difficult, just a little messy. Here are my additions:
1. Loosen all the bolts slightly and then decide which direction you want the fluid to drain out. At that side, loosen and remove several bolts that are next to each other. As you move from that side of the pan toward the "hinge" side of the pan, loosen the bolts from more to less. You'll reach a point somewhere that the weight of the fluid will overcome the attachment of the gasket to the metal and the pan will start leaking and then pour. I'd like to tell you exactly how it happens, but it can leak just a bit and then gradually increase or it can go "pop" and start pouring quickly. Just have a drain pan ready (and if you are in your driveway, some cardboard under the drainpan to soak up what doesn't make it in the pan)
2. Use some car ramps or jackstands. You'll need to be under the vehicle for a little while and you simply cannot do this job without having some clearance. The more room, the better.
3. When you remove the pan, do make sure that you clean the magnet. It won't even look like a magnet because it has gunk all over it. It'll be sitting in the bottom of the pan in a circular impression. I used paper towels and wiped down the tranny pan to get it nice and clean.
4. When you pull the filter (which is approximately the size of a small book), It has a rubber Oring that must come out with it. If will often stay in the tranny and the filter comes out. When you go to stick the new one it, it won't fit because the oring is still in there. Just make sure it comes out. You can reach in with a finger and pop it out.
5. Pay attention BEFORE you pull the filter out how it is in there. It has a ring sort of device that it snaps onto tubes on the bottom of your tranny. Just look at where it clips onto those tubes so that when you reassemble, you'll put it in the same place. (pictures work good for this)
6. My tranny has a reusable gasket that is very good. I suspect yours does too. If it is black rubber and has two ridges on each face, its quite a bit better than any cork gasket they'll sell you. Just clean it up and reuse it.
Other than that, it's an easy job. I didn't install a drain plug in mine, but they do exist. I just can't speak to the ease of install. Frankly, I've always wondered why cars aren't made with tranny drain plugs and external filters, like the oil.
Good luck and I hope you get it running again. If you do, post another query about how to change your oil. You'll be surprised at how easy it is.
Mark