Originally Posted by gcalo
If it's not leaking I'd leave it alone.
Don't invite trouble.
It wasn't leaking and I didn't mess with it.
Thanks again to KyleB for posting this DIY.
I used an OTC (2359) Oil Suction Gun to fill the fluid. It was ~$18 from Amazon and worked a lot better than the cheap plastic types.
I decided to use Motocraft Mercon SP transmission fluid.