It has a fill plug, dipstick and a drain plug. The fluid is a proprietary fluid, Motorcraft XT-7-QCFT. Your best bet is to get it online from Tasca or another Ford dealer that sells parts online--the fluid is expensive. You should only use this fluid.
There's a dipstick, though if it's not leaking I'd just drain and fill. There's also a fill bolt. Checking the fluid is tricky, as it expands much more than typical ATF. Unless you have a way to pull the transmission temp, check it hot, in neutral with the car running. In order to access the dipstick, you have to pull the airbox out of the way. The dipstick is buried underneath it. It's black, and hard to see. At full temp, the correct level is 12mm ABOVE the top hole.
If the fluid level is correct, just drain the fluid hot, let it get to room temp, measure how much came and and add the fluid. The drain plug is either a T40 or a 6mm allen. Do yourself a favor and order a new drain plug (the new ones are 6mm steel). The T40 are aluminum and they strip easily. If there's a T40 on there, use a high-quality bit and tap that sucker in hard before you try to remove it. The fill bolt is accessed from the top. It takes a 3/8" drive. You'll need a long socket extension, 18" or so. This is also accessed with the air box removed or bent up out of the way.
Lastly, there are two filters on this car-a full flow "high pressure" filter, and a pan filter. I wouldn't bother with the pan filter unless the pan is weeping, or 150K, whichever comes first. The HP filter needs to be changed, though. It's recommended in the service manual at 60K, though I think you go to 100K on the OEM filter without much trouble. I wouldn't go over that, though. The filter change is a bit of a bear, since you need to remove a wheel and engines/trans mount and support the transmission for access. It's not difficult, just tedious.
Fluid capacity it 10 qt. I'd get 7 qts. A drain and fill should get out 6-6.5 of fluid. A filter swap removes about a pint.